Update team ownership
Update team ownership

As I will not be maintaining the ovn-octavia-provider, I
am removing my name from the list. Also, since I have
not been as active in L3 recently, update that as well.

Change-Id: Ie883044f3bedc09ff19c58ce90ab9fdc09b92e29

openstack/neutron,mahak/neutron,openstack/neutron,mahak/neutron,openstack/neutron,mahak/neutron