Block attempts to transfer encrypted volumes until [1] gets resolved.
[1] documents the fact that encryption keys are not properly transferred
to the new volume owner. Resolving this will be tricky because Key
Managers such as Barbican currently provide no API for transferring
ownership, and Key Manager ACLs are insufficient because they don't
allow the new volume owner to delete the key.
[1] https://bugs.launchpad.net/cinder/+bug/1735285
Related-Bug: #1735285
Change-Id: I5dbeb46adc9da1fce6359a96b981aa8d673d50c4
04d7e2d80d