core: BaseImagesCommand - update disk volume type

BaseImagesCommand -> endSuccessfully: update disk's VolumeType/VolumeFormat.
Specifically in bug context, needed when moving a raw/thin provisioned disk
from file domain to block domain.

Change-Id: I34f32dfdc0dcf8bad14d114371d9bd0a7314913c
Bug-Url: https://bugzilla.redhat.com/1098258
Signed-off-by: Daniel Erez <derez@redhat.com>