add copyright to the template as well

templates/src/csharp/build_packages.bat.template

 %YAML 1.2
 --- |
+  @rem Copyright 2016, Google Inc.
+  @rem All rights reserved.
+  @rem
+  @rem Redistribution and use in source and binary forms, with or without
+  @rem modification, are permitted provided that the following conditions are
+  @rem met:
+  @rem
+  @rem     * Redistributions of source code must retain the above copyright
+  @rem notice, this list of conditions and the following disclaimer.
+  @rem     * Redistributions in binary form must reproduce the above
+  @rem copyright notice, this list of conditions and the following disclaimer
+  @rem in the documentation and/or other materials provided with the
+  @rem distribution.
+  @rem     * Neither the name of Google Inc. nor the names of its
+  @rem contributors may be used to endorse or promote products derived from
+  @rem this software without specific prior written permission.
+  @rem
+  @rem THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+  @rem "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+  @rem LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+  @rem A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+  @rem OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  @rem SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  @rem LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  @rem DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  @rem THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  @rem (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  @rem OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  
   @rem Builds gRPC NuGet packages
   
   @rem Current package versions