Starts os activity indicator.

Please be warned that this informs os ui system to start. For actual animation to take effect you usually need to wait till the end of this frame. So if you want activity indicator to be animated during synced operation, please use coroutines.

	IEnumerator Load()
    {
        #if UNITY_IPHONE
            Handheld.SetActivityIndicatorStyle(iOSActivityIndicatorStyle.Gray);
        #elif UNITY_ANDROID
            Handheld.SetActivityIndicatorStyle(AndroidActivityIndicatorStyle.Small);
        #endif
        Handheld.StartActivityIndicator();
        yield return new WaitForSeconds(0);
        Application.LoadLevel(1);
    }
    void OnGUI()
    {
       if( GUI.Button(new Rect(10, 10, 200, 200), "Load!") )
            StartCoroutine(Load());
    }