Merge "Add mdns files and unit tests" am: 57852487b8 am: 165cee4902

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2098221

Change-Id: Ided36b7a2d17d55dd91dca829e8818bfc429b753
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>