[RTT2] Direct Aware Responder configuration

Direct Aware Responder configuration set to the basic rates (discovery
channel 6, 20MHz bandwidth). It is expected that these will be ignored
and that (with a Ranging enabled Responder Publisher) enabled on the peer
a high accuracy RTT will be negotiated.

Bug: 67678464
Test: unit test & integration test (non-functional at this point)
Change-Id: I240cfef91a968cd1eb75a71b5ead96ae4eccb32d