Reassign IP to vlan interface when deleting a VLAN bridge

When deleting a VLAN bridge that has an IP address assigned to it, don't delete
the VLAN interface, but reassigned the IP address back to the underlying VLAN
interface.

Closes-Bug: #1255153

Change-Id: I5e39877c0786b43eddba9b5e1394d4c2ec023c0a
Merge "Reassign IP to vlan interface when deleting a VLAN bridge"