Disable ForceNew for project sink unique_writer_identity field (#8845) (#15721)

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/8845.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+logging: supported in-place update for `unique_writer_identity` in `google_logging_project_sink`
+```

google/services/logging/resource_logging_project_sink.go

@@ -39,7 +39,6 @@ func ResourceLoggingProjectSink() *schema.Resource {
 		Type:        schema.TypeBool,
 		Optional:    true,
 		Default:     false,
-		ForceNew:    true,
 		Description: `Whether or not to create a unique identity associated with this sink. If false (the default), then the writer_identity used is serviceAccount:[email protected]. If true, then a unique service account is created and used for this sink. If you wish to publish logs across projects, you must set unique_writer_identity to true.`,
 	}
 	return schm

google/services/logging/resource_logging_project_sink_test.go

@@ -335,7 +335,7 @@ resource "google_logging_project_sink" "described" {
   filter      = "logName=\"projects/%s/logs/compute.googleapis.com%%2Factivity_log\" AND severity>=ERROR"
   description = "description updated"
 
-  unique_writer_identity = false
+  unique_writer_identity = true
 }
 
 resource "google_storage_bucket" "log-bucket" {
@@ -470,7 +470,7 @@ resource "google_logging_project_sink" "bigquery" {
   destination = "bigquery.googleapis.com/projects/%s/datasets/${google_bigquery_dataset.logging_sink.dataset_id}"
   filter      = "logName=\"projects/%s/logs/compute.googleapis.com%%2Factivity_log\" AND severity>=WARNING"
 
-  unique_writer_identity = false
+  unique_writer_identity = true
 }
 
 resource "google_bigquery_dataset" "logging_sink" {