Android: Switch AudioTrack to the AudioFormat.ENCODING_PCM_16BIT

[dkaukov]

This PR makes two key changes to improve audio playback and handling:

1. Switches AudioTrack to use AudioFormat.ENCODING_PCM_16BIT for better device compatibility.
2. Updates the wire transfer format to int8_t to address issues with Android USB drivers.

Rationale

1. Better Compatibility:
   Some devices don’t support PCM 8-bit , as documented [here](https://developer.android.com/reference/android/media/AudioFormat#ENCODING_PCM_8BIT). Switching to PCM 16-bit ensures consistent playback across devices.
2. USB Driver Fix:
   Android USB drivers can add zeros to audio chunks ([issue](Missing/Corrupt data with high baud rates. mik3y/usb-serial-for-android#599)). Using int8_t, where 0 represents silence, minimizes audio artifacts caused by this bug.

[VanceVagell]

Please merge the latest changes in main into this and resolve any conflicts. The Android app DB has changed schema, so I can't easily install this to test it (my devices are using the new schema).

[dkaukov]

@VanceVagell merged

[VanceVagell]

I'm hearing audio artifacts as of this PR, please see attached test video. Listen at 0:16, 0:17, and 0:24. There is some popping.

It was subtle in that recording, but earlier I was hearing a lot of popping when first testing this. Reminds me of small buffer underruns, but not 100% sure that's what this is.

(Note that I merged with the latest in main again to test this, which adds UHF support. Please merge on your side as well.)

screen-20250120-221459.mp4

[VanceVagell]

I retested on main without your PR and I still hear the clicking, so it's unrelated, was just a red herring.

Please merge once more and I think we're good to finalize this PR.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[dkaukov]

@VanceVagell re-merged and tested. Seems ok to me.
BTW This is was causing crash:

moduleTypeSetting.value.equals("UHF")

in java it is better to do:

   "UHF".equals(moduleTypeSetting.value)

to be null safe (it would not help in this particular case, though)

this is null safe for this case:

radioAudioService.setRadioType(
    "UHF".equals(Optional.ofNullable(moduleTypeSetting).map(setting -> setting.value).orElse("VHF")) 
    ? RadioAudioService.RADIO_MODULE_UHF 
    : RadioAudioService.RADIO_MODULE_VHF
);