Vlan and Flat Networks should not install flows learnt by other OVSs

InterfaceAddWorkerOnElanInterface calls setupEntriesForElanInterface which calls installEntriesForElanInterface which calls programRemoteDmacFlow.
programRemoteDmacFlow iterates over all DPNs in the ELAN, learns all MACs from them and installs them in the DMAC TABLE.
This should be avoided and be learnt from packet ins.