am "am f35e8159: am 99b91b2f: am c9dbaf04: Merge "Doc change: refactor GCM docs to be platform-agnostic." into lmp-docs automerge: 2b36779f"

merged from goog/mirror-m-wireless-internal-release
5788e258 am f35e8159: am 99b91b2f: am c9dbaf04: Merge "Doc change: refactor GCM docs to be platform-agnostic." into lmp-docs automerge: 2b36779f