feat(#AlwaysOnMagnifier)!: Supports activated field in MagnificationConfig

After supporting magnification zooming to 100%, we can not identify whether
the controlling magnifier is activated or not when we get scale = 1.0f in
MagnificationConfig instance. Therefore, we add a new field activated to help
identify the magnifier activated state.

Besides, we adjust related classes to provide or handle with correct
activated state.

Bug: 146504199
Test: atest MagnificationProcessorTest
      atest MagnificationControllerTest
Change-Id: I5969e576ff7c93aa72382e6d14571659f7017106