Add copyright headers to remaining gyp files.

gyp/android_output.gyp

+# Copyright 2015 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
 # GYP file to send android SkDebug to stdout in addition to logcat. To enable,
 # include this project as a dependency.
 {
   'targets': [
     {
       'target_name': 'android_output',
       'type': 'static_library',
       'sources': [
         '../tools/AndroidSkDebugToStdOut.cpp',
       ],
       'dependencies': [
         'skia_lib.gyp:skia_lib',
       ],
     },
   ],
 }