feat: Supported project-level-budgets in Public Budget API V1

Added `scope` for project scope filter in `ListBudgetsRequest`. When this field is set to a project's resource name, the budgets returned are tracking the costs for the given project.

feat: Added `enable_project_level_recipients` for project owner budget emails

Setting this field to true will enable email notification to project owners for project-level budgets.

PiperOrigin-RevId: 559152052

google/cloud/billing/budgets/v1/BUILD.bazel

@@ -205,7 +205,9 @@ php_gapic_library(
     rest_numeric_enums = True,
     service_yaml = "billingbudgets.yaml",
     transport = "grpc+rest",
-    deps = [":budgets_php_proto"],
+    deps = [
+        ":budgets_php_proto",
+    ],
 )
 
 # Open Source Packages
@@ -283,7 +285,6 @@ ruby_gapic_assembly_pkg(
 
 csharp_proto_library(
     name = "budgets_csharp_proto",
-    extra_opts = [],
     deps = [":budgets_proto"],
 )
 

google/cloud/billing/budgets/v1/budget_model.proto

@@ -224,6 +224,16 @@ message NotificationsRule {
   // account.
   bool disable_default_iam_recipients = 4
       [(google.api.field_behavior) = OPTIONAL];
+
+  // Optional. When set to true, and when the budget has a single project
+  // configured, notifications will be sent to project level recipients of that
+  // project. This field will be ignored if the budget has multiple or no
+  // project configured.
+  //
+  // Currently, project level recipients are the users with `Owner` role on a
+  // cloud project.
+  bool enable_project_level_recipients = 5
+      [(google.api.field_behavior) = OPTIONAL];
 }
 
 // A filter for a budget, limiting the scope of the cost to calculate.
@@ -260,8 +270,10 @@ message Filter {
   // Optional. A set of folder and organization names of the form
   // `folders/{folderId}` or `organizations/{organizationId}`, specifying that
   // usage from only this set of folders and organizations should be included in
-  // the budget. If omitted, the report includes all usage for all
-  // organizations, regardless of which organization the usage occurred on.
+  // the budget. If omitted, the budget includes all usage that the billing
+  // account pays for. If the folder or organization contains projects that are
+  // paid for by a different Cloud Billing account, the budget *doesn't* apply
+  // to those projects.
   repeated string resource_ancestors = 2
       [(google.api.field_behavior) = OPTIONAL];
 

google/cloud/billing/budgets/v1/budget_service.proto

@@ -150,6 +150,14 @@ message ListBudgetsRequest {
     }
   ];
 
+  // Optional. Set the scope of the budgets to be returned, in the format of the
+  // resource name. The scope of a budget is the cost that it tracks, such as
+  // costs for a single project, or the costs for all projects in a folder. Only
+  // project scope (in the format of "projects/project-id" or "projects/123") is
+  // supported in this field. When this field is set to a project's resource
+  // name, the budgets returned are tracking the costs for that project.
+  string scope = 4 [(google.api.field_behavior) = OPTIONAL];
+
   // Optional. The maximum number of budgets to return per page.
   // The default and maximum value are 100.
   int32 page_size = 2 [(google.api.field_behavior) = OPTIONAL];