gestures: Allow disabling mouse scroll acceleration

- Adds new boolean property to indicate scroll acceleration is off
- Adds new int property to indicate the user scroll speed setting

This change is guarded behind a feature flag in UI
(allow-scroll-settings).

BUG=b:292079653
TEST=unittests and tested locally on a Logitech MX Master 3X mouse
on DUT with flags (#allow-scroll-settings) on

Change-Id: I3bcfee84e8f6c9c15a78ac8eff08ca56137501fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/gestures/+/4704360
Reviewed-by: Sean O'Brien <seobrien@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Wenyu Zhang <zhangwenyu@google.com>
Reviewed-by: Kenneth Albanowski <kenalba@google.com>
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>
Tested-by: Wenyu Zhang <zhangwenyu@google.com>
3 files changed