NewPipe_PreUnified-v0.19.9.7

Fixed

1. Update extractor to fix YouTube comments not showing
2. Fix build due to jcentre shutdown, use forked versions of ExoPlayer and groupie libraries
3. Update youtube regex in extractor to fetch webm audio streams (a regression introduced in earlier release)
4. Fix: the best audio track should always be selected when downloading video (YouTube)

Improved

1. Remember Playback adjustment step size in (speed and pitch) in PlaybackParameterDialog