During upgrade tests, Rook should verify that it can still run legacy
OSDs. This includes directory-based OSDs, filestore disk OSDs, and
bluestore disk OSDs installed without ceph-volume (i.e., before mimic
v13.2.2) can still be run after upgrade.

This necessitates running the upgrade test twice; once with filestore
and once with bluestore.
Signed-off-by: Blaine Gardner <blaine.gardner@suse.com>