Unify voice interactor and recognizer settings.

There is now one settings UI to select both the new
voice interactor and old voice recognizer.

There are still a few wonky things about this that won't
be resolved until we start requiring that all interactors
specify an associated recognizer service.

Change-Id: Ib702ff717fb28bcb244cb30e49577066ddc9f197
7 files changed