By default, when loadbalancer VIP ports are created (either via Octavia
or via neutron-lbaas (v2)), then the port is created with
admin_state_up=False (i.e. the port is disabled). Dragonflow respects
this attribute, and does not 'wire' the port in this case.
Rather than change the default in Octavia and neutron-LBaaS, this patch
detects this case, and enables the VIP ports.
Change-Id: Ibbe927b2672f327349bdd9cff46349d4d01c990a
Partial-Bug: #1720734