Add WindowMagnificationAnimationController for animation

WindowMagnificationAnimationController provides same
functionality but it runs the animation while
enabling/disabling.

This new patch also fixs NPE excetion that happens
when device is in rotation but mirrorWindow is invisible.

Bug: 161669184 163026794 163035371
Test: atest com.android.systemui.accessibility
atest WindowMagnificationGestureHandlerTest
manual Test: enable window magnification to see it
        2. close mirroe window and rotate the device

Change-Id: I4531f5c96ea4b91b287cc8c5ffc4c98fc9611dd5