Issue #3275883 by tedbow, phenaproxima: Warn if cron updates are enabled and the site is on an unsupported branch
Issue #3281634 by Theresa.Grannum, hestenet: VersionPolicyValidator::getAvailableReleases() does not need to be static
Issue #3280180 by phenaproxima, tedbow: Consolidate all version validation logic into a single class