Make invocation of rapi test configurable by QA config

This does not solve the underlying problem of the rapi test not
being runnable locally, but it makes it at least configurable
to avoid having to patch in/out all the time.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>