title: nsTemplateKey ignored in NativeScript ListView
body: <p>I'm attempting to use two templates in a ListView, but the ListView always picks the first template. The callback function is returning the correct value for the template key to no effect.</p>
  
  <p>Markup:</p>
  
  <pre><code>&lt;ListView row="0" [items]="eventRoll.people" (itemTap)="onItemTap($event)"
    [itemTemplateSelector]="templateSelector"&gt;
    &lt;template nsTemplateKey="absent" let-item="item"&gt;
      &lt;Label  style="background-color:lightblue" [text]="item.isAccounted ? 'here' : 'absent'"&gt;&lt;/Label&gt;
    &lt;/template&gt;
    &lt;template nsTemplateKey="here" let-item="item"&gt;
      &lt;Label  style="background-color:lightgreen" [text]="item.isAccounted ? 'here' : 'absent'"&gt;&lt;/Label&gt;
    &lt;/template&gt;
  &lt;/ListView&gt;
  </code></pre>
  
  <p>TypeScript:</p>
  
  <pre><code>public templateSelector = (item: Person, index: number, items: any) =&gt; {
    let key = item.isAccounted ? "here" : "absent";
    return key;
  }
  </code></pre>
  
  <p>I've simplified the markup, so that the only difference is the background color. Whichever template is first is being used regardless of the nsTemplateKey.</p>
  
  <p>What am I missing? Why aren't the templates being used according to the key?</p>