OVS port delete does not delete interface-state

The following cherry-pick from master has broken interface-manager in stable/oxygen :

https://git.opendaylight.org/gerrit/#/c/71833/

This is because interface-manager in stable/oxygen does not use ManagedTransactionRunner and in that case, we need explicit transaction.submit() in the handler. The patch was cherry-picked unknowingly from master,and was not caught in any of the CSITs so far. But this can result in a lot of stale entries remaining in OVS, when a VM is deleted, without deleting a neutron port in case of netvirt.

The issue was detected while we were testing our in-progress SRM test suite in stable/oxygen