fix(#Magnification): reset gesture handler state when magnifier deactivates

Add FullScreenMagnificationGestureHandler as MagnificationInfoChange callbacks for FullScreenMagnificationController, so that when fullscreen magnifier resets the gesture handler would be notified and reset the state.

Bug: b/271520937
Test: manually
      atest FullScreenMagnificationControllerTest
      atest FullScreenMagnificationGestureHandlerTest
      atest MagnificationControllerTest
Change-Id: I605dbd7b0c29fb056dca6afd89d4316db7e71a08