Music.java: Remove superfluous method, use isStream().
Music.java: Remove superfluous method, use isStream().

hurzl/dmix,jcnoir/dmix,abarisain/dmix,0359xiaodong/dmix,abarisain/dmix,0359xiaodong/dmix,jcnoir/dmix,hurzl/dmix,joansmith/dmix,joansmith/dmix