fix halo display in pie

Change-Id: Ie6885c7de7c97e71515b2269c87fbec16e99e500
Don't enable GPS if the requesting app is blacklisted.

This is transparent to the app, it just sees no location callbacks as
before. It just avoids the additional unneeded battery drain.

Change-Id: Iff98bcc3a4ff724aea8763e08b687441bda9ede0