Revert "Remove ComputerTracker and fix consistency in PackageManagerService"

This reverts commit 2fd993fd6cab961e524e858274cdc55789d9ed72.

Reason for revert: test monitor, was identified as culprit for b/223768516

Change-Id: I871e5ab1c9cbe083a4aea4e916eb45a820725155
42 files changed