Extend documentation for AAudio stream disconnect handling on P and Q

The tech note on disconnected audio streams describes a [workaround](https://github.com/google/oboe/blob/main/docs/notes/disconnect.md#workaround-for-not-disconnecting-properly) to detect disconnected streams with `ACTION_HEADSET_PLUG`. Unfortunately, this isn't adequate to detect all cases an AAudio stream may be disconnected, for instance routing changes based on Bluetooth state changes. We've recently become aware as well that resuming from a call interruption or using the "play" function on a Bluetooth device can cause audio to re-route.

Is there a single Java API or comprehensive set of APIs that can be used to reliably detect stream disconnects? Would it be possible to add this recommendation to the technical note?