[REQUIRED] Use case description

Allow playback of 'native' FLAC without requiring use of the FLAC extension on Android O MR1 and above. Starting from this version of Android, the platform shipped with a built in FLAC decoder that's accessible via MediaCodec.

Proposed solution

• A Java based FLAC extractor in the core library. Unlike FlacExtractor in the FLAC extension, this implementation will only do extraction (the FLAC extension FlacExtractor also does decoding).
• Once completed, we should consider whether or not it makes sense to deprecate and eventually remove FlacExtractor in the FLAC extension.

Alternatives considered

N/A