message: Add the licenses
diff: +/* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
  +
  +Licensed under the Apache License, Version 2.0 (the "License");
  +you may not use this file except in compliance with the License.
  +You may obtain a copy of the License at
  +
  + http://www.apache.org/licenses/LICENSE-2.0
  +
  +Unless required by applicable law or agreed to in writing, software
  +distributed under the License is distributed on an "AS IS" BASIS,
  +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  +See the License for the specific language governing permissions and
  +limitations under the License.
  +==============================================================================*/
  #include "gtest/gtest.h"
  #include "tensorflow/c/experimental/filesystem/filesystem_interface.h"
  #include "tensorflow/c/tf_status_helper.h"
  