With ZMQ enabled between fpmsyncd to orchagent, default routes are set to DROP #3978
Description
Recently ZMQ was enabled in sonic-mgmt (refer to sonic-net/sonic-mgmt@111e635).
fpmsyncd sends a DEL+SET for every route. This was coalesced by the producerStateTable infra. But with ZMQ enabled, this coalescing does not happen. As a result, orchagent gets a DEL+SET for every route. This works well normally. But for default routes, there is a bug in orchagent, where it adds a DROP action when it receives the DEL. But when the subsequent SET is received, it does not reset it to FORWARD action. This is due to a bug in its checking code.