Initial replacement of setOutline() with ViewOutlineProvider API

bug:15283203

A View's outline is now managed by its outline provider. This means
the outline is automatically requeried when needed (e.g. drawable
updates or resize), with customizable querying behavior.

Also adds 'isFilled' property to outline, to be used for hinting
shadow overdraw avoidance.

Change-Id: Ie137548fa850f1ff7863ab2f660d05145c2ad11e