BatteryStats: Fix coalescing of shared app GIDs and system UIDs

UIDs that consumed power and were actually shared app GIDs are now
coelsced for system apps as well as regular applications. In addition,
system UIDs like logd, NFC, DRM, etc are coalesced into Android System.

Bug:23189342
Change-Id: I6c8eb4baec66fba3d1f71a155d8ea1fe920ffec9