message: Fix broken distributed_runtime/remote_device_test by adding missing
  std::shared_ptr.
diff: @@ -49,8 +49,9 @@ class RemoteDeviceTest : public ::testing::Test {
  TF_CHECK_OK(spec.AddHostPortsJob("localhost", {hostport}));
  ChannelCreationFunction channel_func =
  ConvertToChannelCreationFunction(NewHostPortGrpcChannel);
  - worker_cache_.reset(
  - NewGrpcWorkerCache(NewGrpcChannelCache(spec, channel_func)));
  + std::shared_ptr<GrpcChannelCache> channel_cache(
  + NewGrpcChannelCache(spec, channel_func));
  + worker_cache_.reset(NewGrpcWorkerCache(channel_cache));
  remote_name_ = "/job:localhost/replica:0/task:0";
  wi_ = worker_cache_->CreateWorker(remote_name_);
  }
  