[OVN] ovn-metadata-agent: Retry registering Chassis at startup
[OVN] ovn-metadata-agent: Retry registering Chassis at startup

This patch adds a retry mechanism on the register_metadata_agent()
method from the OVN metadata agent to make it more tolerable to the
start up order of the services.

Change-Id: If0e5a64e5f692c781fb5e6a68b948b611c694ab0
Closes-Bug: #1905700
Signed-off-by: Lucas Alvares Gomes <ef89b923b1145c9ec2fd96eee513279016a7a963@gmail.com>

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