Right CLick on res folder -> New Android Resource Directory - select resource type raw -> ok and move your file to this folder
Even if its showing unresolved reference: raw in the Android Studio, it does still run. when I did the rebuild it didn't show any error during the build. just put the right path like R.raw.myrawfile and run it, the app will run.
if u want the red mark on the code to go away you probably have to restart (do invalidate cache and restart)