tests/audio: add an invalid settings test As we are going to change the related code next. Reviewed-by: Mark Cave-Ayland <mark.caveayland@nutanix.com> Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>