Add a timeout for the DNS probe.

Bug: 129312219
Test: atest NetworkStackTests
Test: atest --generate-new-metrics 50 NetworkStackTests:com.android.server.connectivity.NetworkMonitorTest
Change-Id: Ib3ab9105d7ae39f551b51e8d5a04b9ec5e549655
Merged-In: Ib3ab9105d7ae39f551b51e8d5a04b9ec5e549655
(cherry picked from commit c7204f689dc58c3ac84818cb1f8fb9add307d90c)
3 files changed