Add a music apps view to the Storage Settings.

When you tap the Music & Audio preference, it takes you a
hybridized applications view. In this view, there also is
a line item which defines the amount of storage used by
audio files on the device. Using the new storage query, we
can add this information very quickly to the view.

Bug: 33199077
Test: Settings robo tests
Change-Id: If51cba0b3de20805543a39049367eb13613081e7