Fix issue #17671802: "content" command always prints...

..."uid 2000 does not have android.permission.UPDATE_DEVICE_STATS"

Make sure to clear calling identity before getting into the guts
of the activity manager.  Also fix the places the activity manager
calls in to battery stats to not require a permission check, anyway.

Change-Id: Ifd90937875b9fe0c36aa3f5cf1ec173746914e6b
3 files changed