Allows neutron-agents l3 agent to communicate with OVS

The neutron-agents l3 agent requires access to the OVS database via
access to /run.  It also needs to have ovs-vsctl binary available in
the container.

Change-Id: I903537b570cd60c9bb1088e9408a5f6ea4988d8f
Closes-Bug: #1477376