netd: Consolidate restrict apps methods

* These are lineage additions (that originated
  from caf).

* addRestrictAppsOnData, addRestrictAppsOnVpn and
  addRestrictAppsOnWlan all do a similar thing
  (fw/b passes different interface arguments).

* Consolidate into addRestrictAppsOnInterface
  (and removeRestrictAppsOnInterface)

* Requires corresponding fw/b services change.

Change-Id: Ic780e943583e616c137c42aa4a72f7af63d02dce