Updating the upstream "ceph-radosgw" package fails with yum errors when the RHEL machine is subscribed to in the "rhel-6-server-rh-common-rpms" channel, why?

Issue

• An Object Gateway configured to work with a Ceph cluster (installed using upstream Ceph packages) is installed with the upstream 'ceph-radosgw' package.

• The cluster is configured using the upstream Inktank Ceph Enterprise packages, running on top of Red Hat Enterprise Linux 6 machines.

• The Object Gateway machine being a RHEL machine, is subscribed to the 'rhel-6-server-rh-common-rpms' channel.

• A regular 'yum update' causes clashes between existing 'ceph-radosgw' package and the same package from the 'rhel-6-server-rh-common-rpms' channel.