Aurora 0.1.76 - corresponding third-party audio decoder sources

FFmpeg 6.1.4, LGPL 2.1 or later. Exact unmodified source archive included under
.tools/audio-codec-build (SHA256 a231e3d5742c44b1cdaebfb98ad7b6200d12763e0b6db9e1e2c5891f2c083a18).
AndroidX Media3 1.8.0 audio Java/JNI, Apache 2.0, included with copyright headers.
Local Java change: package-level explicit UnstableApi opt-in. No video renderer.
Only AC3 and E-AC3 enabled; no network, demuxers or video decoders in this library.

Build on Windows: install Android NDK 26.3.11579264 in .tools/android-sdk/ndk/;
extract the FFmpeg archive beside itself. Install Git/MSYS shell and coreutils;
adjust gitBin in scripts/build-audio-codecs.ps1 to that usr/bin directory.
The original build used MSYS2 coreutils 8.32-5 chmod/ln/od in .tools/audio-codec-build
and Git usr/bin on PATH for their dependent DLLs. Package URL:
https://repo.msys2.org/msys/x86_64/coreutils-8.32-5-x86_64.pkg.tar.zst
SHA256 62dfee1c39fd15f99c39802b35e82643bc14fffc16d6c76d4001caa385ec77e3.
Use PowerShell 7 and run scripts/build-audio-codecs.ps1 from this root.
The script contains all configuration, compilation and linking commands for
arm64-v8a, armeabi-v7a and x86_64; generated shared libraries are placed under
android/decoder-ffmpeg/lib/<ABI>/libffmpegJNI.so. The APK loads that shared library
dynamically. checksums.properties records the distributed binary hashes.
Java classes compile against Media3 1.8.0 and checker-qual 3.43.0 (compile only).
Changes to the library can be built using this procedure and substituted in a
locally rebuilt/re-signed APK. No Aurora credentials or proprietary app source
are contained in this archive.

Upstream:
https://ffmpeg.org/releases/ffmpeg-6.1.4.tar.xz
https://github.com/androidx/media/tree/1.8.0/libraries/decoder_ffmpeg
