[macos] Some audio files miss spectrum data when another audio file plays first

To reproduce this, run the following on macOS:

1. Run Ensemble8
2. Run the "Audio Bar Chart" sample (or "Advanced Media")
3. Run the "Audio Area Chart" sample
BUG: No audio spectrum data will be shown in the area chart

If you run the "Audio Area Chart" sample first after starting Ensemble, it works correctly.

It works correctly on Windows and fails on macOS (I tried both 10.13.6 and 10.15.4 and it fails on both).

This appears to be a regression from the removal of CoreAudio, JDK-8232589. If I do a build from the commit right before CoreAudio was removed, it works. If I then do a build from right after CoreAudio was removed, it fails.