Begins refactoring delete into test and execute steps

This change is the first in a series that breaks the deletePackageLIF
method into two distinct steps: testing for ability to delete and actual
execution of the delete. This is part of the larger effort of removing
exception cases during atomic install commit.

Bug: 109941548
Test: install, uninstall still work
Change-Id: Ib4f7799044cb7d6a346da35160046ee5d9ce0b0c