Unfortunately, PackageKit is horribly broken and the fix I've submitted over a year ago (RHBZ#1847124) has still not landed. Because all the CentOS repos are broken with PackageKit without this fix, we'll just have to ship our own, as unfortunate as it is.
Metadata Update from @ngompa: - Issue assigned to ngompa
This is in progress: https://cbs.centos.org/koji/buildinfo?buildID=35139
I've tagged it for release now, so this is done.
Metadata Update from @ngompa: - Issue status updated to: Closed (was: Open)
Metadata Update from @ngompa: - Issue tagged with: new-package