Manila has changed from using subfolders to subvolumes.
We need a bit of a tidy up to prevent deploy errors.
This change also adds the ability to specify the ceph FS
Manila uses instead of relying on the default "first found".

Closes-Bug: #1938285
Closes-Bug: #1935784
Change-Id: I1d0d34919fbbe74a4022cd496bf84b8b764b5e0f