title: How does the calendar app change icon dynamically? (pixel android nougat)
body: <p>I notice that the calendar app change entry icon every day.<br>
  I googled and read this:<br>
  <a href="https://stackoverflow.com/questions/1103027/how-to-change-an-application-icon-programmatically-in-android">How to change an application icon programmatically in Android?</a> <br>
  Use <code>activity-alias</code> or <code>shortcut</code> can change app icon. If use <code>activity-alias</code> way, calendar need to write 31 <code>activity-alias</code> node, horrible! If use <code>shortcut</code>, app need two <code>uses-permission</code> and maybe launcher show a toast when app try to add a shortcut.<br>
  Can I change icon like calendar app? Help!</p>