Feature Request: Improve fast play speed setting granularity

Description

Currently the fast play speed is configured via a ListPreference with limited options; it would be helpful to have more versatility in customizing the speed, while watching lectures for example.

Expected behavior

The fast play speed setting UI provides a wider range of options.

Screenshot / video

This is my take at this: shezik/vlc-android@4fb712e3

The ListPreference is replaced with SeekBarPreference, offering fine-grained control over the value, ranging from 1.25x to 8x in 0.25x increments. It'd be great if this could be merged!

App mode

Smartphone