Refactor display color transforms

- Removed Secure.ACCESSIBILITY_DISPLAY_COLOR_MATRIX, it's not desirable
  to persist the actual color transformation matrix.
- Refactored all SurfaceFlinger transforms to DisplayTransformManager,
  which allows color transforms to be set independently from the a11y
  manager service.

Bug: 30042357
Change-Id: Iefa477dedb66aac90e1218e327802a3fab6899ed