Added javadoc comments to prevent unused parameter warning.

android-project/src/org/libsdl/app/SDLActivity.java

@@ -937,10 +937,18 @@ public boolean deleteSurroundingText(int beforeLength, int afterLength) {
 /* A null joystick handler for API level < 12 devices (the accelerometer is handled separately) */
 class SDLJoystickHandler {
 
+    /**
+     * Handles given MotionEvent.
+     * @param event the event to be handled.
+     * @return if given event was processed.
+     */
     public boolean handleMotionEvent(MotionEvent event) {
         return false;
     }
-
+
+    /**
+     * Handles adding and removing of input devices.
+     */
     public void pollInputDevices() {
     }
 }