Bug 1079974 - [Loop] Ringer should be played through the main speaker

See bug https://bugzilla.mozilla.org/show_bug.cgi?id=1079974 please.
> why this check is needed here and in the rest of the code is not needed? thanks
We lazy load the audio competing helper object under several circumstances. There were chances in which the terminate function was called and the audio competing helper object wasn't loaded yet. Maybe we need to double-check this because the app flow has been changed a bit. I really prefer to keep it.