Revert "core: When ActivateVDS fails, move VDS out of Unassigned status"

This reverts commit ae49a3b702c166c87d5e2992a5d12591cd785a3b as this solution is not standard.

Change-Id: I4a91e20142f36de1ddae12bfcf63f684823e4358
Signed-off-by: lzelkha@redhat.com
Bug-Url: https://bugzilla.redhat.com/962180