Bug 872848 - [Settings] 'Disco Drive' ringtone sound is lower than other sounds

by mail discussed with Patryk Adamczyk on 5/30.
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Thanks, I tested it on device, and it sounds fine (no audible clipping).
Part of this change can we also change the following, basically remove "soft" from the names, since is not softer anymore, so the distinction doesn't make sense.

File name from:  ringer_soft_disco_drive.opus to ringer_disco_drive.opus
In settings > sounds > ringtones, the ringtone should now read: Disco Drive not Disco Drive (Soft)