message: docs: move draft status to Google gRPC only
  The main gRPC service message is no longer draft.
diff: @@ -14,7 +14,6 @@ import "gogoproto/gogo.proto";
  option (gogoproto.equal_all) = true;
  // [#protodoc-title: gRPC services]
  -// [#proto-status: draft]
  // gRPC service configuration. This is used by :ref:`ApiConfigSource
  // <envoy_api_msg_core.ApiConfigSource>` and filter configurations.
  @@ -26,6 +25,7 @@ message GrpcService {
  string cluster_name = 1 [(validate.rules).string.min_bytes = 1];
  }
  + // [#proto-status: draft]
  message GoogleGrpc {
  // The target URI when using the `Google C++ gRPC client
  // <https://github.com/grpc/grpc>`_. SSL credentials will be supplied in
  