title: Will savedInstanceState always be null if the user does not explicitly modify it?
body: <p>According to Android's developer pages: </p>
  
  <blockquote>
    <p>Because the onCreate() method is called whether the system is creating
    a new instance of your activity or recreating a previous one, you must
    check whether the state Bundle is null before you attempt to read it.
    If it is null, then the system is creating a new instance of the
    activity, instead of restoring a previous one that was destroyed.
    <a href="https://developer.android.com/guide/components/activities/activity-lifecycle#restore-activity-ui-state-using-saved-instance-state" rel="nofollow noreferrer">Source</a></p>
  </blockquote>
  
  <p>From what I understand, this means a conditional <code>if(savedInstanceState == null)</code> inside <code>onCreate()</code> will only run on the first instance of Activity; If the user switches between apps or changes orientation, the system will call <code>onCreate()</code> and the above conditional will return <code>false</code> and the code inside will not be executed, as expressed by the following code.</p>
  
  <pre><code>@Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
  
      // Check whether we're recreating a previously destroyed instance
      if (savedInstanceState == null) {
          // Code here will run only on the *first* time onCreate() is called
      } 
  
      // Code here will run every time onCreate() is called
  }
  </code></pre>
  
  <p>But will the code above work as expected if <code>saveInstanceState</code> object is never explicitly modified by the user?</p>
  
  <p>From the above quote, it seems that a change in orientation will modify <code>saveInstanceState</code> in some way as to have the conditional described above return <code>true</code>.</p>
  
  <p>I have been looking into the topic and I find no relevant information on how the system is modifying <code>savedInstanceState</code> behind the scenes (or if it is doing that at all).</p>
  
  <p>So the question is:  Will <code>savedInstanceState</code> always be <code>null</code> if the user does not explicitly modify it?</p>