Merge "Set up and tear down test network in TestNetworkRunnable" am: 1e071f9120 am: 83f08bd8ee

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1503692

Change-Id: I4b57cc2b0d1f3f6c6e01dc2eed9c63d42d253ad9