nightly_revert_checker: update branch name

Android updated this branch name, so we have to reflect that here.

BUG=b:182277561
TEST=None

Change-Id: Ia709901bf8544eb751bc4c736f9e351640c52329
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2746504
Reviewed-by: Pirama Arumuga Nainar <pirama@google.com>
Reviewed-by: George Burgess <gbiv@chromium.org>
Tested-by: George Burgess <gbiv@chromium.org>
1 file changed