b26c4316cb
In previous, we only use a variable to record the state of magnification
mode. Therefore, it would be confused when there are multiple displays.
Now, we use sparse array to keep the state of current magnification mode
and last magnification activated modes with corresponding displayId,
making us have ability to distinguish different modes in different
displayId.
Bug: 182227245
Test: atest MagnificationControllerTest
atest MagnificationProcessorTest
atest FullScreenMagnificationGestureHandlerTest
atest MagnificationConfigTest
Change-Id: I239faab22bb6abe3e6cadde9b09eba496c4688c0