title: cdkFocusInitial attribute not focusing the DOM element
body: <p>In Angular 10 project, I have a form with 2 inputs named Username and Password. I am using
  <code>cdkFocusInitial</code> attribute on username field, however it's not focusing on page load. Here is a StackBlitz example that shows the issue <a href="https://stackblitz.com/edit/angular-4amzj4?file=src%2Fapp%2Ffocus-monitor-directives-example.html" rel="noreferrer">https://stackblitz.com/edit/angular-4amzj4?file=src%2Fapp%2Ffocus-monitor-directives-example.html</a></p>
  <pre><code>&lt;div class=&quot;example-focus-monitor&quot;&gt;
  
      &lt;mat-form-field appearance=&quot;fill&quot;&gt;
          &lt;mat-label&gt;Username&lt;/mat-label&gt;
          &lt;input cdkFocusInitial  aria-label=&quot;Username&quot; class=&quot;username&quot;
               matInput
              placeholder=&quot;Enter Username&quot; type=&quot;text&quot;&gt;
    &lt;/mat-form-field&gt;
  
          &lt;br/&gt;
          &lt;mat-form-field appearance=&quot;fill&quot;&gt;
      &lt;mat-label&gt;Password&lt;/mat-label&gt;
      &lt;input   aria-label=&quot; Password&quot; class=&quot;password&quot;  matInput placeholder=&quot;Enter Password&quot;
              type=&quot;text&quot;&gt;
          &lt;/mat-form-field&gt;
  &lt;/div&gt;
  
  
    
  
  
    [1]: https://stackblitz.com/edit/angular-4amzj4?file=src%2Fapp%2Ffocus-monitor-directives-example.html
  </code></pre>