Currently we maintain a separate variables for repository configuration
for Debian and EL platforms. With that these variables are not available
for override in group/host_vars, which makes it tough to maintain
different client versions between multiple availability zone.
So this patch brings in alignment in a variables that are used for
different platforms along with enabling deployers to define them
in group_vars.
Depends-On: https://review.opendev.org/c/openstack/openstack-ansible/+/929636
Change-Id: I1d90143d59423a9411ed9eeed1faf61d99551f4d
90deaaa8eb