title: checked = "checked " stops working when I add ngModel in mat-checkbox
body: <p>My mat-checkbox's checked = "checked" stops working when I add an ngModel to it.</p>
  
  <p>This will work.</p>
  
  <pre><code>&lt;mat-checkbox name="BlackBeard" ngModel checked = "checked"&gt; Zehahaha? &lt;/mat-checkbox&gt;
  </code></pre>
  
  <p>This will not work.</p>
  
  <pre><code>&lt;mat-checkbox name="BlackBeard" ngModel checked = "checked"&gt; Zehahaha? &lt;/mat-checkbox&gt;
  </code></pre>
  
  <p>Note : I require a solution that is generic. I want to use it in a scenario, where I am dynamically generating checkboxes. Although binding it to vairiables is a solution, i want one where i dont have to do that.</p>