Grant auto-submit permission to same group as CQ+2

This keeps people without CQ+2 permission from being about to use
auto-submit to CQ+2. Will find a way to limit auto-submit to change
owners with CQ+2 permissions later—just closing the hole for now.

Change-Id: Ibd3edf93f3b71c2d2bc3f3f2254a15ed6ca8ef7a
Reviewed-on: https://pigweed-review.googlesource.com/c/Public-Commit-Queue-Projects/+/30100
Reviewed-by: Nathan Mulcahey <nmulcahey@google.com>