Merge "Improve error reporting in ConnDiags tests" am: 01aa602a3f am: 78a9b27ca5 am: 252558dcdd

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1925681

Change-Id: I408e0d129604a3460bdd2fc2726c2e60d152edd7