Add RebootTargetPreparer for tests that require root permission am: 37a894be am: 05e757b4

Original change: https://android-review.googlesource.com/c/platform/packages/modules/DnsResolver/+/2323393



Change-Id: Ie70d7854705993e6aa72f3ee6548101bebca68cf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>