Makes non-system app deletion fail-safe

This is the second in a series of app delete refactors that moves
detection of all failure cases outside of the actual delete action for
non-system apps (system apps still require a subsequent install of the
disabled app that can still fail).

Bug: 109941548
Test: install, uninstall still work
Change-Id: I8ee470fdb02f2ae9cea1da0f23f484242c47173b