core, userportal: Cannot add AD group to a new VM from the user portal

After creating a new VM from the user portal,
it's not possible to add an AD group to the VM

Change-Id: I9cce0e664b5bbe0110a03f41e1d6eb9c822cf8ef
Bug-Url: https://bugzilla.redhat.com/1114041
Signed-off-by: Ravi Nori <rnori@redhat.com>