Revert "Add forwarding methods to RoutingCoordinator"

This reverts commit 55ccfe19e24e0fdeab1c8c736a94da2478e65890.

Reason for revert: this must be introducing some sort of race
it appears to cause
  atest EthernetTetheringTest 'NetdBinderTest#TetherForwardAddRemove'
to no longer reliably pass.

Change-Id: I5281ab3f42c5ce268d97a12db24a6768db3f4354
6 files changed