new shouldInterrupt logic: screen on, not locked, not dreaming, and
priority above HIGH and noisy, or has fullscreen intent
draft of API allowing devs to give hints about head up display
reuse inflateViews()
add an expand helper to the heads up space
move some things into Entry for reuse
don't allow touches in first second
delay decay if touched
make decay time a resource
add a custom viewgroup for notification rows to get view management
out of the NotificationData class.
Change-Id: I36464f110cfa0dabc3f35db7db6c35c27e8ee2ba
51c7510e49