When using ovn as neutron plugin, the health probe failed with "RabbitMQ
sockets not Established" error, because it still check TCP connection to
Rabbitmq while OVN metadata agent doesn't use Rabbitmq. This patch adds
a condition check to avoid tcp socket state check for ovn metadata agent.
Story: #2010686
Change-Id: Ic35c1b4bb3c4d1cff7b633e6f69d5269cc23eeef
84a6df2e5d