Rework the interface for ID3v2 text frames by:
- Switching from a mutable array to ImmutableList
- Never leaving the array empty, instead filling it with "" if there
are no values
This makes the surface safer and more in line with the rest of the
module.
ExoPlayer extensions are modules that depend on external libraries to provide
additional functionality. Browse the individual extensions and their READMEs to
learn more.