Revert "Move libvirt RBD utilities to a new file"

This reverts commit cb8968400f8c8370cab309de0f63e82565bfb25b.

The series of patches involved with adding this feature introduced
an unexpected dependency on glance's v2 API, which we do not
currently support. Triggering a user-facing bug quickly, and leaving
some uncertainty about what else is likely to come in the future,
a revert of this code was decided given the short time to -rc1.

Change-Id: I5e5d897f7294a7d4bda76ed392f503d0552f45e9
Related-bug: 1291014
Merge "Revert "Move libvirt RBD utilities to a new file""