base

Improved the heads up logic to launch fullscreen intents less

Fullscreen intents are always less distracting when heads upped
instead of launched fullscreen, so when snoozed or if the ranking
isn't high enough we now prefer HUN instead of simply launching
it.

Change-Id: Iae16d35c6a6d3f11f3d1f6db6e1dc067018a5172