Adding HomeGestureMonitor

It listens to touchpad three fingers swipe up gesture but is not used anywhere yet.
Also extracting common three finger gesture logic to ThreeFingerGestureMonitor.

Bug: 346576895
Test: HomeGestureMonitorTest
Flag: com.android.systemui.shared.new_touchpad_gestures_tutorial
Change-Id: If8f5b7e6a5ce8cbf5da9b9d582bc33f2dc9cf950