rewrite details in property inspector. make system sounds the default fallback behavior

src/FocusVolumeControl/DialAction.cs

@@ -16,14 +16,13 @@ public class DialAction : EncoderBase
 {
 	private class PluginSettings
 	{
-
-		[JsonProperty("onVolumeNotFound")]
+		[JsonProperty("fallbackBehavior")]
 		public FallbackBehavior FallbackBehavior { get; set; }
 
 		public static PluginSettings CreateDefaultSettings()
 		{
 			PluginSettings instance = new PluginSettings();
-			instance.FallbackBehavior = FallbackBehavior.PreviousApp;
+			instance.FallbackBehavior = FallbackBehavior.SystemSounds;
 			return instance;
 		}
 	}