Android close Dialer programmatically

Question

I am initiating a phone call from an activity and would like to close the dialer automatically after 7 seconds (and end the phone call).

This code doesn't work:

private static final int REQUEST_CALL = 135;
private long nCallShouldEndAfterMs = 7 * 1000;

private void callNumber()
{
    Intent callIntent = new Intent(Intent.ACTION_CALL);
    callIntent.setData(Uri.parse("tel:" + sMyNum));
    startActivityForResult(callIntent, REQUEST_CALL);

    scheduleClosingDialer();
}


private void scheduleClosingDialer()
{
    handler.postDelayed(new Runnable()
    {           
        @Override
        public void run()
        {
            try
            {
                Log.d(TAG, "closing dialer");
                finishActivity(REQUEST_CALL);
            }
            catch(Exception e)
            {
                Log.w(TAG, "Dialer already closed");
            }               
        }
    }, nCallShouldEndAfterMs);
}