Currently when the connection to the coordinator is closed, the consumer will immediately try to rediscover the coordinator and reconnect to it. This is fine as it is, but the NetworkClient enforces a blackout period before it will allow the reconnect to be attempted. This causes the following cycle which continues in a fairly tight loop until the blackout period has completed:
1. Notice connection failure (i.e. DISCONNECTED state in ConnectionStates)
2. Send GroupCoordinator request to rediscover coordinator.
3. Attempt to connect to coordinator.
4. Go back to 1.
To fix this, we should avoid rediscovery while the connection is blacked out.