feat(#AlwaysOnMagnifier): Add haptic and buffer zone when panning scale to persisted scale

In FullScreenMagnificationGestureHandler, support vibration feedback and create buffer zone when panning scale to persisted scale. It's to help user stay on preferred zoom level when panning scale.

Besides, with always on feature enabled, the magnifier would set scale to 100% and keep activated after transitions. The changes in this CL help user return to persisted scale quickly.

Bug: 269476411
Test: manually - attach video in b/269476411
      atest FullScreenMagnificationGestureHandlerTest
      atest AccessibilityMagnificationTest
Change-Id: I4a607e5ad402d0d69b9236e4ccf5979850dfc49c