Make runtime permission check return granted for pre-M apps

... if they have requested it, of course.

Pre-M apps would never expect the permission to be revoked, and we
rely on app op for the final decision. This change allows us to use
the actual permission state to store/derive the app op state.

Bug: 136503238
Test: atest CtsAppSecurityHostTestCases CtsPermissionTestCases
Change-Id: I9473a265a5eadef994d8bddb0700c08ad10ba654