title: Is it possible to use an external image as notification icon?
body: <p>I want to let users could select an external images in sdcard as notification icon. However, it seems to be impossible, and only an internal image with resource id could be used as notification icon.</p>
  
  <p>Therefore, I may need a method to set a bitmap as notification icon.</p>
  
  <p>Sample for notification, and only the resource id could be set as notification icon not a bitmap.</p>
  
  <pre>
  int icon = R.drawable.notification_icon;
  CharSequence tickerText = "Hello";
  long when = System.currentTimeMillis();
  Notification notification = new Notification(icon, tickerText, when);
  </pre>
  
  <p>Also, I know that a Custom Expanded View for notification is possible to use external image, but still it's not for notification icon. </p>
  
  <p>Appreciated.</p>