Add context to net-lb-app-ext module (#3879)

modules/net-lb-app-ext/backend-service.tf

@@ -46,7 +46,7 @@ resource "google_compute_backend_service" "default" {
   for_each = var.backend_service_configs
   project = (
     each.value.project_id == null
-    ? var.project_id
+    ? local.project_id
     : each.value.project_id
   )
   name                            = coalesce(each.value.name, "${var.name}-${each.key}")