Also update copywrite header to conform to expectations.

BUG=chromium:1082354
TEST=locally, can upload commit with this fix

Change-Id: I5527cf9cc58fbab94f777b82008a422a3190f539
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2199884
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>