rbd pools are not initialized with "pool init"

[Giulio Fidente]

It seems that since mimic, pools to be used for RBD should be initialized with specific "rbd pool init" command [1]; we don't seem to be doing this [2]

1. https://docs.ceph.com/en/pacific/rbd/rados-rbd-cmds/#create-a-block-device-pool
2. https://github.com/openstack/tripleo-ansible/blob/master/tripleo_ansible/ansible_plugins/modules/ceph_pool.py

[Giulio Fidente (gfidente)]

in tripleo scenarios all but the manila pools will be used for RBD I think; rgw pools are created by the daemon when it starts

alternatively, to be on the safe side, maybe we can do this for those pools which get "rbd" application assigned?