Changing GestureState to sealed classes instead of enums

First phase of introducing live tracking of gestures.
Moving GestureState to classes is required because InProgress will include current progress.

Bug: 369817369
Test: Only small refactoring, code compiles and tests pass
Flag: com.android.systemui.shared.new_touchpad_gestures_tutorial
Change-Id: I5d7858c3c1a0fe51588eb1933a0171c1e79fccb3