Wrap code making the assumption there is only one Ceph backend
(using is_ceph_volume_configured) in a "range" and use
ceph_backend_list helper to iterate all available Ceph backends.
Move Ceph pool application name in values.yaml from
conf.software.rbd.rbd_pool_app_name* to conf.ceph.pools.*.app_name
Change-Id: If1126e51fe9ebb85185e375dc282e83db63d934c
Depends-On: Iaa67061b05a9d355228ad7d3f5ee0f4f04dbdc66
Signed-off-by: Daniel Badea <daniel.badea@windriver.com>