Revert "Ensure ApplicationInfo is for correct user for system/android package."

Cache in ActivityThread means this still doesn't make sure we will
get an ApplicationInfo for the user being requested. So reverting.

This reverts commit 4a3b8aa08d743b28d53b327597abf03a925641f2.

Bug:17002733
Change-Id: Ie40eb31c4074cea09de3d6a41fe38b14e00eb059