Don't access iface_arr unless using OVS

Change-Id: I3829f4aeb9d8072597fa68a71280c5444c2ab34e
Default to ovs_use_veth = True on non-Fedora systems

Change-Id: I13309932c221b1738ecaec4cdf06a4ec27155b1e
Merge "Don't access iface_arr unless using OVS"