According to the Octavia API, a provider driver should
set the member operating_status field to OFFLINE on a
create if admin_state_up=False in the call. The OVN
provider wasn't looking at that flag, so always had
operating_status set to NO_MONITOR (the default when
health monitors are not supported).
Also, when a member is updated from admin_state_up=False
to True, operating_status must show NO_MONITOR since no
health monitor is configured and the status is unknown.
(cherry picked from commit