The NumberPicker input cotrols are somtimes not shown.

bug:3452868

1. Now hiding the input controls, which also cancels the input controls
   fade-in animation, on every intercept of down since the fade-in
   anumation flips a flag used to guide the drawing of the input controls.
   Note that we also want the scroll wheel shown on down but the fade-in
   anumation is actually hiding it upon completion.

Change-Id: Ib161ed757e537365b21e6913370d264152dca1fe