[automerger skipped] Test that if an RA sets the same prefix as DNS, nothing happens. am: fbf205a380 am: bc7b68512d -s ours am: bcf6db2cea -s ours am: 2de2cc19ef -s ours

am skip reason: Change-Id I3316d49d42100800740afadc4edf0a13a4d8377c with SHA-1 4afb82b32e is in history

Change-Id: I2617d3198e686417098f8f47d6133579d13f89dc