Use volume utils to clone encryption
Use volume utils to clone encryption

clone_encryption_key was introduced in volume_utils from this
patch https://review.opendev.org/#/c/523225/. We should use
this utils rather than the method of key manager.

Change-Id: I7f391233a7f5c383b883b6a14312220dafd0dbd9

mahak/cinder,openstack/cinder,openstack/cinder,mahak/cinder