STL add support for overlays in snapToIdleIfClose()

If the transition is close to the current Content, we can immediately
switch to the Idle state.

Test: atest SceneTransitionLayoutStateTest
Bug: 377503459
Flag: com.android.systemui.scene_container
Change-Id: I0b0df74516d550a0618ef3118c5ac74d5fb3a96a
3 files changed