Do not run POLICY_REJECT_ALL migration in Restore

The Restore process does not expect or need to do a migration of UID
policies, and in fact, doing so causes problems; after a Restore,
the policies are already set as expected, so do not mess with them.

Issue: calyxos#2638
Change-Id: I50fca8f76c143d90821535df9c79746672e35447