Settings: disable wifi display from search indexing if disabled

If wifi display is disabled from the system property or from
the overlay file, disable its key indexing to stop appearing
it in search result. Also update the database version to reflect
the changes.
Also fix indexing for saved access point settings.

Issue-id: YAM-141

Change-Id: Ia3688e4b294ad67ab8029dd47d1067fd722cbff7