[NAN] Add support for NAN RTT.

Provide API for NAN RTT through WifiNanManager. While NAN RTT could be executed
directly through RttManager the peer information is hidden by WifiNanManager (no
MAC address is exposed). Using WifiNanManager keeps the information hidden.

Bug: 26564277
Change-Id: I8deeb3f9e360dc05f2ea175d115f287590d50322
6 files changed