PackageManager: Fix logic around upgrading text display

* This code has all threads writing into the integer keeping track of
  the number of packages at once.
* Make this integer an atomic one, preventing all threads from racing
  when updating it.

Change-Id: I727306f8ab20edb7ec2a955ca20e6de0146c7737
Merge remote branch 'cm/cm-11.0' into cm-11.0