ceph-common: convert ceph_stable_rh_storage to ceph_rhcs in main task
ceph-common: convert ceph_stable_rh_storage to ceph_rhcs in main task

Signed-off-by: Alfredo Deza <adeza@redhat.com>

Resolves: issue#811

font/ceph-ansible,guits/ceph-ansible,WingkaiHo/ceph-ansible,jtaleric/ceph-ansible,font/ceph-ansible,bengland2/ceph-ansible,travmi/ceph-ansible,travmi/ceph-ansible,albertomurillo/ceph-ansible,guits/ceph-ansible,albertomurillo/ceph-ansible,verdurin/ceph-ansible-1,fgal/ceph-ansible,WingkaiHo/ceph-ansible,fgal/ceph-ansible,albertomurillo/ceph-ansible,verdurin/ceph-ansible-1,ceph/ceph-ansible,jsaintrocc/ceph-ansible,ceph/ceph-ansible,jtaleric/ceph-ansible,WingkaiHo/ceph-ansible,bengland2/ceph-ansible,jsaintrocc/ceph-ansible