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

Add RebootTargetPreparer for tests that require root permission am: 37a894be am: d5369624 am: 5c52938a

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



Change-Id: I861be75a0f15650cc8e6eb7af5d0e5855a33c70d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>