Settings: create sound dir directory if not existing, improve UX

create "SoundPacks" folder on internal storage if not existing.
also tell the user, if we could create the directory or not.

quote "SoundPacks" in summary to give the user better details,
what exactly we mean and where he should place what.

Change-Id: I9125ab31ef119764f9aa67a68754db6f28c1a5bb