...mismatched uid: X on disk, Y in settings" errors on Froyo and Gingerbread
Deal more gracefully with the uid changing in three ways:
1. If the uid on disk has become root, then have installd change it to
the application's uid. This is to correct a potential case where
installd was interrupted while linking or unlinking the libs dir,
during which it temporarily changes the owner of the dir to root
so that a malicious app can not get in its way. So if the uid on
disk has become root, we assume we can safely just change it back
to the correct uid.
2. When scaning packages at boot, use the same "delete and rebuild data
directory" code for third party applications as we have for system
applications. This allows us to at least end up in a state where the
app will run, even if its data is lost.
3. But we really don't want to get in to case 2, so if an application
update is being installed and we find that the uid we now have for
the app is different than the one on disk, fail the update. This will
protect against for example a developer changing the sharedUserId of
their app and getting into this bad state.
Bug: 6295373
Change-Id: Ic802fdd818ac62449ff3c61d1fff1aa4d4942f39