Don't interpolate the STL size when overscrolling

This CL ensures that we don't interpolate the size of a
SceneTransitionLayout when there is an overscroll defined on the scene
that is overscrolling.

Bug: 291053278
Test: atest SceneTransitionLayoutTest
Flag: com.android.systemui.scene_container
Change-Id: I6cc69b78c806b43903eb9d033116992b457f0cbb
2 files changed