Enable RBD-backed Glance in openstack::all

Although openstack::glance supports using Ceph RBD as a backend,
the openstack::all class currently lacks parameters to enable
RBD-backed-glance in all-in-one installations.  This commit
adds the necessary parameters for users to use Ceph as a backend
for Glance.

Change-Id: I7f7364eb647d9d950ae11d83cf3beef7cd452d6b
Implements: blueprint rbd-backed-glance-in-all