With localnet UDNs a user may be adding bridge-mappings for new NICs via nm state on day 2. Today CNV team ignores managing/modifying "physnet" bridge mappings. With OCP today we support physnet and physnet1 (br-ex1). With OPNET-189 epic, we may have many NICs tied to OVS bridges and new physnet mappings added. We want to make sure CNV does not step on these and similarly the new API here does not step on the bridge mappings added by CNV.