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

[automerger skipped] Fix use-after-free in DNS64 discovery thread am: 292b59e1 am: 93d3a164 am: b1398479 -s ours am: 8e058e2c -s ours am: 99061ba7 -s ours am: 3c770d64 -s ours am: 39e2bdd5 -s ours

am skip reason: Merged-In Id74ea4e6f54a00805d3cc8a9d7e15e58a473b7d3 with SHA-1 79f57106 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/24557576



Change-Id: Ia2896775a5939c4ed1045812fa7cb5e4405f34e1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>