CentOS 8.1 came with HA repo. So we can use it.
hacluster-pcs image is disabled as we lack 'crmsh' package for it.
Partially-Implements: blueprint centos-rhel-8
Co-Authored-By: Mark Goddard <mark@stackhpc.com>
Change-Id: I1c786eda399eca4464c9d68ac040c2965350f775
92224ccb51