Makes only one activated magnifier on the display when the controlling...

Makes only one activated magnifier on the display when the controlling magnifion magnifier transitions mode

To make only one activated magnification mode
show on the display.
When fullscreen magnifier is turned to be activated on
the display. MagnificationController will disable the
window magnifier if it is enabled.

Bug: 206820500
Test: atest MagnificationControllerTest
Change-Id: I465e7293b4262d3cf8caf9873ea772aba50f1d6d