Adjust playback speed using left screen swipe gesture instead of brightness control

[cortana99]

I often adjust the playback speed multiple times while watching a video.

• Faster while watching recaps
• Slower through sections that I'm not familiar with and need the additional time for my brain to comprehend

It would be more efficient to adjust the playback speed using a swipe gesture. I rarely use the brightness control gesture so it would be nice to have the option in the settings to reassign the brightness control gesture to playback speed control.

I primarily watch educational content which I think this feature would be the most useful for, but there are likely other use cases as well.