fix: Minor changes based on review comments.

Author: freezy

VisualPinball.Unity/VisualPinball.Unity.Editor/Sound/SoundComponentInspector.cs

@@ -96,7 +96,6 @@ private bool AllTargetsSupportLoopingSoundAssets()
 
 		protected void InfiniteLoopHelpBox(VisualElement container)
 		{
-			var soundAssetProp = serializedObject.FindProperty("_soundAsset");
 			var helpBox = new HelpBox("The assigned sound asset loops, but this component " +
 				"provides no mechanism to stop it or is not configured to do so. Either assign" +
 				" a sound asset that does not loop or (if possible) configure this component to" +

VisualPinball.Unity/VisualPinball.Unity/Sound/SoundAsset.cs

@@ -75,8 +75,7 @@ private enum SelectionMethod
 
 		public void ConfigureAudioSource(AudioSource audioSource, float volume = 1)
 		{
-			audioSource.volume = Random.Range(_volumeRange.x, _volumeRange.y);
-			audioSource.volume *= volume;
+			audioSource.volume = volume * Random.Range(_volumeRange.x, _volumeRange.y);
 			audioSource.pitch = Random.Range(_pitchRange.x, _pitchRange.y);
 			audioSource.loop = _loop;
 			audioSource.clip = GetClip();