It sometime takes a short time for removal to be reflected in get_ceph_pool_sample so wrap check in tenacity decorator to retry.
Porting the Amulet tests from Cinder Backup to the Zaza framework. The Amulet tests can be found here: https://opendev.org/openstack/charm-cinder-backup/src/commit/4273738b94b22cca187487af2bad982be49fdd69/tests/basic_deployment.py