Auditor exits silently on ZK timeout

**BUG REPORT**

***Describe the bug***

Autorecovery running standalone:

```
2022-06-14T05:14:25,461 [main] INFO org.apache.bookkeeper.client.BookKeeperAdmin - Resetting LostBookieRecoveryDelay value: 0, to kickstart audit task
2022-06-14T05:14:25,461 [main] DEBUG org.apache.bookkeeper.meta.ZkLedgerUnderreplicationManager - setLostBookieRecoveryDelay()
2022-06-14T05:14:25,612 [main] INFO org.apache.zookeeper.ZooKeeper - Session: 0x3000418b60b0047 closed
2022-06-14T05:14:25,612 [main-EventThread] INFO org.apache.zookeeper.ClientCnxn - EventThread shut down for session: 0x3000418b60b0047
2022-06-14T05:14:25,612 [main] INFO org.apache.bookkeeper.meta.ZkLedgerAuditorManager - Shutting down AuditorElector
```

after loss of ZK connectivity.

Eventually this can get to the situation when there is no Auditor in the cluster.

***Expected behavior***

Auditor shutdown should either result in the thread restart/attempted reconnect to ZK, if needed or should trigger AR service's shutdown/fail healthcheck so k8s has a chance to restart the service.