Make copyright headers consistent with Google template; remove "(C)"

Test: Comment changes only; still compiles...
Change-Id: Id699a8170112f06e4a2c9f2e0f0834d1817ace4e
diff --git a/.gn b/.gn
index 947ebac..1c2396d 100644
--- a/.gn
+++ b/.gn
@@ -1,5 +1,5 @@
 #
-#  Copyright (C) 2015 Google, Inc.
+#  Copyright 2015 Google, Inc.
 #
 #  Licensed under the Apache License, Version 2.0 (the "License");
 #  you may not use this file except in compliance with the License.