Add a boolean flag for sys app scanned as stopped

This boolean flag in PackageSetting will be set to true if a system app
was initially scanned in the stopped state.

Bug: 297360102
Bug: 295084647
Bug: 297788394
Bug: 294330522
Bug: 296180087
Test: presubmit
Test: manual
Change-Id: Id6a3d7332e9562407b1fb4c645c682013d71b505