[Thread] add an integration test case for resolving a host via DNS recursive resolver

This CL adds new test cases for verifying the Thread Border Router's
DNS Recursive Resolver feature: The DNS clients resolves google.com
successfully when the feature is enabled.

Bug: 354868095
Test: atest ThreadNetworkIntegrationTests:android.net.thread.InternetAccessTest

Change-Id: I1b021151c6843b30c3f47559ab20dec405af5dea
3 files changed