Android build support

[XP20]

Hello, I have gotten the app to build and run on Android.
https://github.com/XP20/supersonic/tree/android-build (added android build support)
https://github.com/XP20/go-mpv/tree/use-pkg-config (1-liner change to use #cgo pkg-config: mpv)

libmpv and transient deps for android are sourced from https://github.com/mpv-android/mpv-android apk /lib/ contents

While audio playback, seeking, track changes, volume all seem to work, caveats include:

• server config (probably settings too) does not persist
• no Android Media Controls integration
• and of course no mobile UI currently

I'd be down to do further work on mobile integration, but at the same time I have never used Go before.

[dweymouth]

I am personally not interested in doing the work myself to build a mobile layout and integrate with mobile APIs like Android Auto. Also I use iOS so don't have a device to test with. But if you implement it I might consider merging and supporting it especially if you or someone could maintain the F-Droid releases. But it would be a lot of work and there are already a lot of great Android clients out there!

[XP20]

Ok yeah, I'm also not super interested in building the mobile layout, I guess I'll try to leave my fork up if anyone wants to try building this for android