Revamping of the NumberPicker widget for improved usablility.

1. Now if the widget is not interacted with shows a smaller selector
   wheel with the increment and decrement arrows at the top and bottom
   respectively.

2. Tapping an arrow button now animates the widget to the new value. i.e.
   rotates the selector whell to the next value.

3. Fixed a bug that double tapping on the input shows the IME but then
   after pressing an arrow button the IME is not hidden.

4. Fixed a bug that was exposed via late changes in the framework or the
   graphics and was manifested of the selector wheel not having fading
   edges.

bug:5251980
bug:5383502

Change-Id: I4a089dc69b07a3b28a514017cddf786cb9f4af16