greenwave: prepare for critical-path-base group split
    
    See https://pagure.io/fedora-comps/pull-request/797 - we need the
    greenwave policy ready for that change before we land it, so updates
    are gated on the correct tests and Bodhi doesn't crash because
    there is no policy for the new contexts.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>