Supports multiple-display on activated mode recording.

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