Segregate Scale and Refresh support.

Scale and Refresh support aren't part of the mission of selection
support to RecyclerView.

This is a cleanup and separation CL. In a subsequent change
I'll merge remaining event handling from ListeningGestureDetector
into UserInputHandler.

Bug: 64847011
Test: Passing
Change-Id: Ie20a8b998dcf1761b2229e03fd55d6e813d6d6ad