[android] Replace Oboe audio with SDL3 audio (#4338)

Supersedes #4335.

Replaces the Oboe audio backend with SDL3, since we already support it.
A few caveats:

- SDL defines a JVM OnLoad method already, so we have to instead hijack
  NativeLibrary for id_cache initialization
- This also means some internal fields in Double/Integer/Boolean (namely
  `value`) can't be accessed, so I switched those to methods for now.
- SDL Java sources are pulled in from the CI package.
- Since we can't use SDLActivity, `SDL.setupJNI()` handles everything

Signed-off-by: crueter <crueter@eden-emu.dev>

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4338
Reviewed-by: Lizzie and Samuel <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

src/android/app/proguard-rules.pro

@@ -9,6 +9,9 @@
 -keep class org.ini4j.spi.IniBuilder
 -keep class org.ini4j.spi.IniFormatter
 
+-keep class org.libsdl.app.** { *; }
+-keepclassmembers class org.libsdl.app.** { *; }
+
 # Suppress warnings for R8
 -dontwarn org.bouncycastle.jsse.BCSSLParameters
 -dontwarn org.bouncycastle.jsse.BCSSLSocket