Test: Add more helper functions for private DNS validation events am:...

Test: Add more helper functions for private DNS validation events am: 7656f200 am: 71fe7845 am: 210f163d am: 0828c192 am: 03ccb926 am: 239d62b4 am: 05a98beb

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/2685926



Change-Id: Ie0f29988acddc8f6b11a95981b441e63f50d5d18
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>