I finally figured this out after probably 5+ hours combined of trying. For the next person in the same boat, here’s the solution for both iOS and Android. I hope this helps someone and saves them from the torment I went through trying to figure this out on my own. The audio file in the example below (alarm.wav) is placed in the root of the www folder. You can adjust that as desired.
<resource-file src=“www/alarm.wav” target=“res/raw/alarm.wav” />
<resource-file src=“www/alarm.wav” target=“res/ios/alarm.wav” />