Add gestures for braille autoScroll commands (#20502)
Fixes #20473
Summary of the issue:
Braille autoScroll scripts don't have associated gestures by default.
Description of user facing changes:
Now, gestures for autoScroll braille commands are available by default:
NVDA+alt+k: toggles autoScroll.
NVDA+alt+j: Decreases scroll rate.
NVDA+alt+l: Increases scroll rate.
