[RTT] Route legacy RTT API on top of new RTT API

Route legacy RttManager API on top of new WifiRttManager API - but
only support the legacy startRanging call. All others (including
Responder modes) are deprecated and throw an exception.

Note: the deprecation tags will be in a separate CL.

Bug: 65108579
Test: unit tests pass
Test: WifiRttManagerTest:test_regular_scan_then_rtt_ranging_stress
Change-Id: I63541fdcaac36f4bb40ed71660bbcfc507693ffc