Coupl'a fixes related to broadcast dispatcher

- Throw an exception instead of a log that no one will see
- Use BroadcastDisaptcher#removeListener in NetworkControllerImpl
- Log NetworkControllerImpl#mListening in dumpsys

Bug: 153712245
Test: atest SystemUITests; manual
Change-Id: I3f4338bfe34126b0adc10ca0116c9149ffaa4115