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

Google APIs · copybara-github · commit fb5fba4d8d9c · 2022-02-17T13:41:57.000-08:00
PiperOrigin-RevId: 429391190
diff --git a/google/bigtable/v2/BUILD.bazel b/google/bigtable/v2/BUILD.bazel
@@ -223,6 +223,7 @@ nodejs_gapic_library(
     package = "google.bigtable.v2",
     service_yaml = "bigtable_v2.yaml",
     deps = [],
+    handwritten_layer = True
 )
 
 nodejs_gapic_assembly_pkg(
