AE: re-add setting normalizelevels, formally inverted and known as boost...

re-add "Normalize downmix matrix" formally known as "Boost volume levels on downmix" which was inverted.
It actually does the same thing as dynamic range compression so I was tempted to drop it but I noticed that CA and RPI depend on this setting.

@popcornmix, @Memphiz what do you think? Still needed?