[automerger skipped] Support setting the default interface to null again. am: 876e5e16a9 -s ours

am skip reason: Change-Id I5109d8da3aeb6c1f6523291d9e2ec92c64b5ad2d with SHA-1 e81f99d532 is in history

Change-Id: I3adadae13ef96c50e4083b8d826730e0fb4990fd
tree: 383b74744be1be63e8bd7e62b7fb70b52491a1a5
  1. service-t/
  2. tests/