Keep the version of dnsresolver consistent with that on mainline-prod. am:...

Keep the version of dnsresolver consistent with that on mainline-prod. am: 9e319503 am: 50719694

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/1470466

Change-Id: I8e7ce37f3d62d2e55b635d7f5f19b891821455f5