docs: Update CreateBucketPubSubNotification to have line without hori…

…zontal scrolling (#1335)



If you write sample code, please follow the [samples format](
https://github.com/GoogleCloudPlatform/java-docs-samples/blob/main/SAMPLE_FORMAT.md).

samples/snippets/src/main/java/com/example/storage/bucket/CreateBucketPubSubNotification.java

@@ -58,7 +58,8 @@ public static void createBucketPubSubNotification(
             .setPayloadFormat(payloadFormat)
             .build();
     Notification notification = storage.createNotification(bucketName, notificationInfo);
-    System.out.println("Successfully created notification for topic " + notification.getTopic());
+    String topic = notification.getTopic();
+    System.out.println("Successfully created notification for topic " + topic);
   }
 }
 // [END storage_create_bucket_notifications]