AppOpsState: Hide undeclared Privacy Guard OPs

Since commit f02e0409
("Settings: Always show Privacy Guard permissions"), all the Privacy
Guard OPs are shown independently on whether the application declared
the associated permission or not. This solved the UI inconsistencies,
but it's still confusing. Instead of always showing these special OPs,
hide them, unless unless the application declared the associated
permission or the OP doesn't have an associated permission.

Note: if a Privacy Guard OP is not associated to any permission it
will appear for every application with Privacy Guard enabled,
bringing back the UI inconsistency solved with f02e0409.
This doesn't happen with the current set of OPs.

Change-Id: Iddc92b3547187e24140a328d50c5ac09bc1a7ccf