create_merge: Add BUG= lines into merge commit message
create_merge: Add BUG= lines into merge commit message

This will trigger the usual gerrit automation to notify the bugs
about the merge being submitted, which will help identify when
fixes have landed in chromeos.

BUG=b:219743659
TEST=./tools/chromeos/create_merge

Change-Id: I6365f3c5596a94a6990caf1e1733e8040e5e8fff
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3469495
Reviewed-by: Noah Gold <2d4550d8af93bfc6e6fbe1fb1b0cc97a9ee7c3ce@google.com>
Reviewed-by: Junichi Uekawa <6bd240a6ce32463e272bb69c685a8e946b33ac05@chromium.org>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Commit-Queue: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>

google/crosvm,google/crosvm,google/crosvm,google/crosvm