[cern] Fix docker-storage configuration
Cherry-pick from [1] for file: magnum/drivers/common/templates/fragments/configure_docker_storage_driver_atomic.sh Revert changes in: magnum/drivers/common/templates/fragments/configure-docker-storage.sh magnum/drivers/common/templates/fragments/configure-cvmfs.sh
Related-Ticket: OS-4106 [1] https://review.openstack.org/#/c/417457/