Support triple-tap and hold for window magnification.

1. Detect triple-tap and hold gesture.
2. Magnify the content at a user's tap location.
3. Offset the frame to the top-left position about a half of frame size
4. The definition and the implementation of
WindowMagnificationController's getCenterX and getCenterY are different
due to these patches. We need to correct them. (ref: b/207812394)

Bug: 202465806
Test: atest IWindowMagnificationConnectionTest
	atest MagnificationControllerTest
	atest WindowMagnificationAnimationControllerTest (@Ignore)
	atest WindowMagnificationConnectionWrapperTest
	atest WindowMagnificationControllerTest
	atest WindowMagnificationGestureHandlerTest
	atest WindowMagnificationManagerTest
Change-Id: I59bf8a3e35e42c963de1698bec915a4a590e5c5f