We allow project.groups to be whitespace or comma delimited, but
repo-hooks.enabled-list is only whitespace delimited. This hasn't
been a big deal as it's only ever had one valid value, but if we
want to add more, we should harmonize these a bit.
Refactor the groups method to be more generic, and run the enabled-
list attribute through it. Then add missing docs for it.
Change-Id: Iaa96a0faa9c4a68b313b49336751831b73bf855d
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/290743
Reviewed-by: Michael Mortensen <mmortensen@google.com>
Tested-by: Mike Frysinger <vapier@google.com>
51e39d536d