Initialize callbacks in fuzzer am: 857ece4f am: 68de805a am: bcba6bc3 am: a85c2ac7 am: 791ea87d am: bcfec392

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/2469762



Change-Id: I21e69bcdb2e557f9bdd573857df6d2815f3fc690
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>