mpeg/es: MP3 files always have VLC_CODEC_MPGA fourcc instead of VLC_CODEC_MP3
MP3 audio files always have VLC_CODEC_MPGA fourcc which is set in modules/demux/mpeg/es.c demuxer. MP3 files should use VLC_CODEC_MPGA fourcc.
This bug prevents chromecast stream_out to distinguish between MP2 and MP3 audio streams, forcing to transcode MP3 to MP3 again.