message: Updates swift gen licence for grpc code
diff: /*
  + * Copyright 2020 Google Inc. All rights reserved.
  *
  - * Copyright 2020, Google Inc.
  - * 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
  *
  - * Redistribution and use in source and binary forms, with or without
  - * modification, are permitted provided that the following conditions are
  - * met:
  - *
  - * * Redistributions of source code must retain the above copyright
  - * notice, this list of conditions and the following disclaimer.
  - * * Redistributions in binary form must reproduce the above
  - * copyright notice, this list of conditions and the following disclaimer
  - * in the documentation and/or other materials provided with the
  - * distribution.
  - * * Neither the name of Google Inc. nor the names of its
  - * contributors may be used to endorse or promote products derived from
  - * this software without specific prior written permission.
  - *
  - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  - * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  - * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  - * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  - * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  + * 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 <memory>
  