HeadsetClient: App exception aren't from SystemServer

Calling into IBluetoothHeadsetClient will call the HeadsetClientService
from Bluetooth app that does not live in the systemServer.
Therefore, exception should be rethrown as runtimeException

Bug: 298264617
Test: atest CtsBluetoothTestCases | Cts does not handled failure in the
      binder nor any of the Test framework we currently have
Change-Id: Iaba3c59907fec05c4285751e475a03507c5d704e