Fix -Wnullable-to-nonnull-conversion errors am: 47936dd7 am: 62a1bd45 am:...

Fix -Wnullable-to-nonnull-conversion errors am: 47936dd7 am: 62a1bd45 am: 4c958592 am: 3e6844d0

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/2526839



Change-Id: I43b9889602b15dd7d9383714dcef43b8494f47b3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>