This is based on comments at
https://github.com/google/shaka-packager/pull/891. The muxer is deciding
whether to write to a single file or a segment file based on the
configuration.
Example:
```
../packager 'in=TOS.ts,stream=video,output=tos_video.ts,playlist_name=tos_video.m3u8' \
'in=TOS.ts,stream=audio,output=tos_audio.ts,playlist_name=tos_audio.m3u8' \
--hls_master_playlist_output tos.m3u8
```
Tested the content using Exoplayer.
---------
Co-authored-by: Cosmin Stejerean <cstejerean@meta.com>
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