message: [XLA:GPU] Include key in error if not found in key-value store.
diff: @@ -29,7 +29,7 @@ KeyValueStore::KeyValueStore() = default;
  // TODO(phawkins): the synchronization here is very coarse, but probably
  // sufficient for its current application.
  if (!mu_.AwaitWithTimeout(absl::Condition(&key_is_present), timeout)) {
  - return ::grpc::Status(::grpc::StatusCode::NOT_FOUND, "");
  + return ::grpc::Status(::grpc::StatusCode::NOT_FOUND, key);
  }
  *value = entries_.find(key)->second;
  return ::grpc::Status::OK;
  