Restore previous semantic for committer check
Created by: davido
During migration to permission backend the committer check was changed. Restore the previous semantic by checking for Submit permission of refs/heads/* as it was the case prior to migration to permission backend. Note, that a change in Gerrit core is needed for that. That's why this change is built against 3.3.0-SNAPSHOT plugin API.
Signed-off-by: David Ostrovsky david@ostrovsky.org