mon: Add mds permissions to client.admin
mon: Add mds permissions to client.admin

The administrator keyring needs full capabilities on mds like mon,
osd and mgr.
Whithout this, the client.admin key won't be able to run commands
against mds (like ceph tell mds.0 session ls)

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1672878

Signed-off-by: Dimitri Savineau <a50a620e679eed14f4e99998b821cea8884cf228@redhat.com>

ceph/ceph-ansible,ceph/ceph-ansible