update ThreadNetworkControllerService to support border routing

This CL lets ThreadNetworkControllerService calls the LocalNetworkConfig
API to set up border routing between Thread and infrastructure network.

Bug: 299552948
Bug: 305861411
Test: Verified on Cuttlefish that forwarding is set up.

Change-Id: I8b2f015d9d6248bfb1cd9ac806dc8664970a26d2