Only delay pressed feedback for Views inside a scrolling parent

Add a method on ViewGroup to determine whether it supports scrolling.
This allows us to show the pressed feedback immediately in many cases,
improving responsiveness of buttons, etc.

This patch also lengthens the timeout in order to reduce flashes
when the user is scrolling.

Change-Id: Ieb91ae7a1f8e8f7e87448f2a730381a53947996f