connectionLost not firing when client is kicked out (duplicate clientId, for example)

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- [x] Bug exists Release Version 1.2.0 ( Master Branch)
- [?] Bug exists in Snapshot Version 1.2.1-SNAPSHOT (Develop Branch)
- [?] Bug exists in MQTTv5 Version (mqttv5-new Branch)

If this is a bug regarding the Android Service, please raise the bug here instead: https://github.com/eclipse/paho.mqtt.android/issues/new

If I connect 2 consumers with the same client id to an MQTT broker using Paho, the first one gets kick out as expected. However, the `connectionLost` callback is never called so I don't know about that until the next time I try to send a message.

How could I know that the client has been kicked out immediately?