Fix: GCS bucket release failing if custom_labels not present (#473)

* Fix: GCS bucket release failing if custom_labels not present

* change in bucket.tf too

Author: anujhydrabadi

modules/google_cloud_storage/default/0.2/bucket.tf

@@ -55,7 +55,7 @@ resource "google_storage_bucket" "bucket" {
   # Labels
   labels = merge(
     var.environment.cloud_tags,
-    var.instance.spec.custom_labels
+    lookup(var.instance.spec, "custom_labels", {})
   )
 
   # Force destroy for easier cleanup in testing

modules/google_cloud_storage/default/0.2/variables.tf

@@ -16,7 +16,7 @@ variable "instance" {
         action        = string
         storage_class = string
       })
-      custom_labels = map(string)
+      custom_labels = optional(map(string), {})
       # location is now fully optional and not required in the type definition
     })
   })