Enforce that onDragStarted.overSlop is != 0f

This CL ensures that the overSlop passed to
SceneGestureHandler.onDragStarter() is different than 0f if we are not
interrupting the current transition.

Bug: 291053278
Test: PlatformComposeSceneTransitionLayoutTests
Flag: N/A
Change-Id: I3300b3b2ceb51a90a15c11d9f67c9b5c10fcbb06
3 files changed