[automerger skipped] Support setting the default interface to null again. am: 356cf6ab82 am: 056047ac70 -s ours am: 773305e533 -s ours

am skip reason: Change-Id I5109d8da3aeb6c1f6523291d9e2ec92c64b5ad2d with SHA-1 356cf6ab82 is in history

Change-Id: I53d8a9896257920d4a3db462a7f3a1c8974361fa
tree: 383b74744be1be63e8bd7e62b7fb70b52491a1a5
  1. service-t/
  2. tests/