Remove all knowledge of tethering from SoftApManager

( dirty cherry-pick from f502d3e20409d81cfefd762b3b44f46dead09a92 )

This logic has moved into Tethering and TetherInterfaceStatemachine,
where it probably always belonged.

Bug: 29054780
Test: WiFi tethering continues to work on angler
      `runtest frameworks-wifi` passes.

Change-Id: Ifff78ea540929fde4abea65716e1f659da2ecfec
3 files changed
tree: 96cbf081d952da66d9c208c5aa0e20cad6cfcd74
  1. service/