Merge pull request #61015 from nbalacha/wip-nbalacha-rbd-mirror-namespace-2

rbd-mirror: default <-> non-default namespace remapping

Reviewed-by: Afreen Misbah <afreen@ibm.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>

diff --cc qa/workunits/rbd/rbd_mirror.sh
Simple merge