These changes are required to configure neutron fwaas in Ocata:
- Allow to configure extensions in neutron l3 agent.
- Allow to configure agent_version in fwaas sections.
- Configure fwaas section in neutron.conf too.
Depends-On: I3f23ac667aee8a4603e866febbfddca2eb299e9b
Change-Id: I780277b7bbf9e14099d0d574c63e31c97a6aa38d