While here, added a presubmit test for the Bug: tag too.

Bug: angleproject:3046
Change-Id: I7030685230b4ce4bfc435c14ef85324e16b76274
Reviewed-on: https://chromium-review.googlesource.com/c/1402061
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>