From API 23, we may have a preferred device that is most likely used
as the output device.
From API 24, the AudioTrack tells us the actual routed device that is
used for output and we can listen to changes happening mid-playback.
From API 33, we can directly query the default device that will
be used for audio output for the current attributes.
If the routed device is known by any of the methods above, we can add
more targeted checks in methods like isBluetoothConnected to avoid
iterating over all devices that are not relevant.
The knowledge about the routed device will also be useful to check
advanced output capabilities in the future (e.g. for lossless
playback)
PiperOrigin-RevId: 600384923
b1c954fa84