Fix -Wnullable-to-nonnull-conversion errors am: 4730f0d7 am: 2920f7e2 am:...

Fix -Wnullable-to-nonnull-conversion errors am: 4730f0d7 am: 2920f7e2 am: a72ac0b2 am: 750a708b

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/2582958



Change-Id: Ic41733d2f5234a9cc0113d512b87cd1ab837db78
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>