build: add flag to distinguish autogenerated libs with a handwritten layer

Google APIs · copybara-github · commit f1529c0002b2 · 2022-02-17T13:42:52.000-08:00
PiperOrigin-RevId: 429391240
diff --git a/google/pubsub/v1/BUILD.bazel b/google/pubsub/v1/BUILD.bazel
@@ -233,6 +233,7 @@ nodejs_gapic_library(
     main_service = "pubsub",
     service_yaml = ":pubsub_v1.yaml",
     deps = [],
+    handwritten_layer = True
 )
 
 nodejs_gapic_assembly_pkg(
