chore: change branch master to main in github configurations (#691)

README.md

@@ -103,27 +103,27 @@ use this Stackdriver Monitoring Client Library.
 
 ## Samples
 
-Samples are in the [`samples/`](https://github.com/googleapis/java-monitoring/tree/master/samples) directory.
+Samples are in the [`samples/`](https://github.com/googleapis/java-monitoring/tree/main/samples) directory.
 
 | Sample                      | Source Code                       | Try it |
 | --------------------------- | --------------------------------- | ------ |
-| Create Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/CreateAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/CreateAlertPolicy.java) |
-| Create Metric Descriptor | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/CreateMetricDescriptor.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/CreateMetricDescriptor.java) |
-| Create Time Series | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/CreateTimeSeries.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/CreateTimeSeries.java) |
-| Delete Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/DeleteAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/DeleteAlertPolicy.java) |
-| Delete Metric Descriptor | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/DeleteMetricDescriptor.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/DeleteMetricDescriptor.java) |
-| Delete Notification Channel | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/DeleteNotificationChannel.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/DeleteNotificationChannel.java) |
-| Enable Disable Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/EnableDisableAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/EnableDisableAlertPolicy.java) |
-| Get Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/GetAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/GetAlertPolicy.java) |
-| Get Monitored Resource | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/GetMonitoredResource.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/GetMonitoredResource.java) |
-| List Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/ListAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/ListAlertPolicy.java) |
-| List Metric Descriptor | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/ListMetricDescriptor.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/ListMetricDescriptor.java) |
-| List Time Series | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/ListTimeSeries.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/ListTimeSeries.java) |
-| Monitored Resources List | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/MonitoredResourcesList.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/MonitoredResourcesList.java) |
-| Quickstart Sample | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/QuickstartSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/QuickstartSample.java) |
-| Time Series Headers List | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/TimeSeriesHeadersList.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/TimeSeriesHeadersList.java) |
-| Update Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/UpdateAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/UpdateAlertPolicy.java) |
-| Uptime Sample | [source code](https://github.com/googleapis/java-monitoring/blob/master/samples/snippets/src/main/java/com/example/monitoring/UptimeSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/UptimeSample.java) |
+| Create Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/CreateAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/CreateAlertPolicy.java) |
+| Create Metric Descriptor | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/CreateMetricDescriptor.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/CreateMetricDescriptor.java) |
+| Create Time Series | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/CreateTimeSeries.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/CreateTimeSeries.java) |
+| Delete Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/DeleteAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/DeleteAlertPolicy.java) |
+| Delete Metric Descriptor | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/DeleteMetricDescriptor.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/DeleteMetricDescriptor.java) |
+| Delete Notification Channel | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/DeleteNotificationChannel.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/DeleteNotificationChannel.java) |
+| Enable Disable Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/EnableDisableAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/EnableDisableAlertPolicy.java) |
+| Get Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/GetAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/GetAlertPolicy.java) |
+| Get Monitored Resource | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/GetMonitoredResource.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/GetMonitoredResource.java) |
+| List Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/ListAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/ListAlertPolicy.java) |
+| List Metric Descriptor | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/ListMetricDescriptor.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/ListMetricDescriptor.java) |
+| List Time Series | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/ListTimeSeries.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/ListTimeSeries.java) |
+| Monitored Resources List | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/MonitoredResourcesList.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/MonitoredResourcesList.java) |
+| Quickstart Sample | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/QuickstartSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/QuickstartSample.java) |
+| Time Series Headers List | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/TimeSeriesHeadersList.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/TimeSeriesHeadersList.java) |
+| Update Alert Policy | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/UpdateAlertPolicy.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/UpdateAlertPolicy.java) |
+| Uptime Sample | [source code](https://github.com/googleapis/java-monitoring/blob/main/samples/snippets/src/main/java/com/example/monitoring/UptimeSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-monitoring&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/monitoring/UptimeSample.java) |
 
 
 
@@ -236,10 +236,10 @@ Java is a registered trademark of Oracle and/or its affiliates.
 [developer-console]: https://console.developers.google.com/
 [create-project]: https://cloud.google.com/resource-manager/docs/creating-managing-projects
 [cloud-sdk]: https://cloud.google.com/sdk/
-[troubleshooting]: https://github.com/googleapis/google-cloud-common/blob/master/troubleshooting/readme.md#troubleshooting
-[contributing]: https://github.com/googleapis/java-monitoring/blob/master/CONTRIBUTING.md
-[code-of-conduct]: https://github.com/googleapis/java-monitoring/blob/master/CODE_OF_CONDUCT.md#contributor-code-of-conduct
-[license]: https://github.com/googleapis/java-monitoring/blob/master/LICENSE
+[troubleshooting]: https://github.com/googleapis/google-cloud-common/blob/main/troubleshooting/readme.md#troubleshooting
+[contributing]: https://github.com/googleapis/java-monitoring/blob/main/CONTRIBUTING.md
+[code-of-conduct]: https://github.com/googleapis/java-monitoring/blob/main/CODE_OF_CONDUCT.md#contributor-code-of-conduct
+[license]: https://github.com/googleapis/java-monitoring/blob/main/LICENSE
 [enable-billing]: https://cloud.google.com/apis/docs/getting-started#enabling_billing
 [enable-api]: https://console.cloud.google.com/flows/enableapi?apiid=monitoring.googleapis.com
 [libraries-bom]: https://github.com/GoogleCloudPlatform/cloud-opensource-java/wiki/The-Google-Cloud-Platform-Libraries-BOM