Fix clang-tidy misc-definitions-in-headers warnings am: 564c1978

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/2314066



Change-Id: I071a60790bc68274e9d6e2506ed0c026ef0c2349
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>