Add delay to deflake mainline tests am: aab50427

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/2288935



Change-Id: Ifcbc2216f559d7ff60087d69540f6bff4a52e60e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>