merge-kernel: Add push-justification for direct push

Per the announcement http://g/gerrit-announce/gOanGgWANGE, a
push-justification is required for a direct push.

Change-Id: I2493a293d99e662e4542128a1893c12656cca2f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5499930
Reviewed-by: Martin Faltesek <mfaltesek@google.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Commit-Queue: William K Lin <wklin@google.com>
Tested-by: William K Lin <wklin@google.com>
1 file changed