[RTT2] Remove Aware RTT code

Original WIP Aware RTT API routed RTT through the Aware manager. This
will be replaced by direct usage of the WifiRttManager API. First step
is to remove the old code.

Bug: 65015034
Test: unit tests pass
Change-Id: I850d285d3f2a3dec6425d933614d18020745b9d4