Fix issue #3154576: battery stats checkin should include UID -> packages+ map

Includes some other small fixes to battery collection and a few
other things.

Output of package info looks like this:

5,0,i,uid,1000,com.android.settings
5,0,i,uid,1000,com.android.providers.subscribedfeeds
5,0,i,uid,1000,com.android.providers.settings
5,0,i,uid,1000,com.android.server.vpn
5,0,i,uid,1000,android
5,0,i,uid,1000,com.android.systemui
5,0,i,uid,1000,com.google.android.backup
5,0,i,uid,1001,com.android.phone
5,0,i,uid,1001,com.android.providers.telephony
5,0,i,uid,1022,com.android.nfc
5,0,i,uid,10021,com.google.android.location
5,0,i,uid,10021,com.google.android.syncadapters.calendar
5,0,i,uid,10021,com.google.android.gsf
5,0,i,uid,10021,com.google.android.syncadapters.contacts
5,0,i,uid,10026,com.android.providers.downloads.ui
5,0,i,uid,10026,com.android.providers.media
5,0,i,uid,10026,com.android.providers.drm
5,0,i,uid,10026,com.android.providers.downloads
5,0,i,uid,10032,com.android.launcher
5,0,i,uid,10039,com.google.android.gm
5,0,i,uid,10041,com.google.android.gallery3d
5,0,i,uid,10049,com.android.providers.calendar

Change-Id: I9e38f254eef146339113ad270f5c6e8b60fb7a1d