[automerger skipped] Fix use-after-free in DNS64 discovery thread am:...

[automerger skipped] Fix use-after-free in DNS64 discovery thread am: 452f032d -s ours am: 38e61896 -s ours am: 46db863d -s ours am: 598a77b3 -s ours

am skip reason: Merged-In Id74ea4e6f54a00805d3cc8a9d7e15e58a473b7d3 with SHA-1 f441eb6b is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/24372273



Change-Id: Id0715cbd0c8a33cd22a336aa222153a848b6e96b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>