STL remove Overscroll DSL [1/2]

New behavior: progress is always in [0, 1]

Typically, a transaction's value falls between 0 and 1. However, if a
transition or animation needs to go beyond these limits, the extra value
or speed is passed on to the OverscrollEffect or the parent elements in
the SceneTransitionLayout.

Test: atest DraggableHandlerTest
Test: atest ElementTest
Test: atest NestedScrollToSceneTest
Test: atest SwipeToSceneTest
Bug: 378470603
Flag: com.android.systemui.scene_container
Change-Id: Ic1b77b99fb7ff3af8085d3d7a67a07bacefd0c7c