Fix Neutron issues related to Baremetal service

When deploying devstack on a single host with a single NIC and
baremetal and neutron services enabled, the host looses Internet
access as default route is deleted.

Also, if localrc is not correctly set with correct values, OVS ports
and Neutron net and subnet aren't created (commands missing
arguments), we need devstack to properly fail.

Change-Id: I7f39bbdf7b8cb544b8b4a59effe16f04b85d1425
Merge "Fix Neutron issues related to Baremetal service"