DO NOT MERGE Remove old APIs that are no longer used/implemented

All of these APIs were hidden and are no longer used by anyone. The scan
APIs are being replaced by the new WifiScanner API

Cherry-picked from 88d93cd68a32e7110f9328ff522226126c7e493e
Change-Id: I36ffef137d0620263278e5ef46bbc498a39c588f
8 files changed