VoiceOver does not voice changed shape in Scenery Demo

[terracoda]

I randomly checked out #1418 (comment) which lead me to Sceneryhttps://phetsims.github.io/scenery/examples/ and I tried some of the examples with VoiceOver and noticed that the hexgaon/circle demo was not voicing the changed state with MacOS VoiceOver.

I think this might be related to a known VoiceOver bug about VO not voicing changes in the PDOM, but maybe not. It is a nice simple example we can use when @jessegreenberg and I talk to Apple Devs.

[terracoda]

I am not assigning anyone, but tagging @jessegreenberg so we can discuss.

[jessegreenberg]

I just tried this example with NVDA and I don't hear the new name there either. I actually wonder if that is expected for this case. When content changes I don't think that is read automatically. This demo mostly is for the input listeners and demonstrates how you can change colors and PDOM content with mouse and keyboard. Maybe we should change the demo slightly so that a screen reader user could read the changed content in the PDOM without holding down a key.