The pause action on `ceilometer-hacluster` occasionally fails `Couldn't pause: Resources still running on unit`. To reproduce, uncomment the [corresponding test class](https://github.com/openstack-charmers/charmed-openstack-tester/blob/master/tests/openstack-upgrade/tests/tests.yaml) and run ``` tox -e openstack-upgrade kitchen-sink-focal-ussuri ```