Library version used: 1.0.0-beta01

Devices/Android versions reproduced on: Any

Android Auto version reproduced on: 6.1.6105

Crash when disconnecting from headunit when navigation is started. Simply start the app, start navigating, disconnect/close dhu. After Android Auto service gets destroyed - this is where we clear NavigationManager callback, this crash occurs.

    java.lang.NullPointerException
        at java.util.Objects.requireNonNull(Objects.java:220)
        at androidx.car.app.navigation.NavigationManager.lambda$onStopNavigation$3$NavigationManager(NavigationManager.java:285)
        at androidx.car.app.navigation.-$$Lambda$NavigationManager$VfCV3KNUFOmGR8cBjFUUBVJugqQ.run(Unknown Source:2)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:246)
        at android.app.ActivityThread.main(ActivityThread.java:8456)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:596)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)

It seems that NavigationManager tries to call onStopNavigation in the callback even though the service is no longer created.