Removed monitoring group set_computed_name post_create

This is now duplicate code.

Author: melinath

mmv1/products/monitoring/Group.yaml

@@ -35,7 +35,6 @@ timeouts:
   update_minutes: 20
   delete_minutes: 20
 custom_code:
-  post_create: 'templates/terraform/post_create/set_computed_name.tmpl'
   custom_import: 'templates/terraform/custom_import/self_link_as_name.tmpl'
 error_retry_predicates: