Status bar brightness control improvements

- Fix status bar brightness control when on secure lock screen.
- Prevent brightness changes after notifications panel has been opened.
- Don't adjust brightness for swipes <45° from vertical.
- Stop using a VelocityTracker

reference:
212c63a250b81676a89f9de145cf4f1b378b43fb
71c97740b5404b3c0be89454e55a69c1ca8655ec
Kill app long press back: use a separate class