Integrate sound generation that is now supported by Slider

[jbphet]

In phetsims/sun#697, generalized support for sound generation by sliders was added. The time was not taken to integrate this into all sims that were doing customized sound generation related to sliders, such as this one. Instead, the default sound was simply turned off via the options. Before this sin is released again off of master, we should consider integrating the now supported method slider sound generation.