title: Last item in list cut off when using cdk-virtual-scroll-viewport for scrollbar
body: <p>I am using cdk-virtual-scroll-viewport to make a scrollbar. It works well, except that the last element is always cut off, no matter how long the list is nor how much i set the itemSize parameter to. (I am using angular 8)
  <a href="https://i.stack.imgur.com/mlakb.png" rel="nofollow noreferrer">picture of cut off last element</a></p>
  <p>This is my code</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>  .gkz-viewport {
      height: 150px;
      width: 320px;
      border: 1px solid black;
      
      .cdk-virtual-scroll-content-wrapper {
        display: flex;
        flex-direction: column;
      }
      .item {
  
      }
    }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code> &lt;cdk-virtual-scroll-viewport class="gkz-viewport" [itemSize]="3"&gt;
    &lt;li *cdkVirtualFor="let app of apps" &gt;
      &lt;custom-apps-row [app]="app" &gt;&lt;/custom-apps-row&gt;
    &lt;/li&gt;
    &lt;/cdk-virtual-scroll-viewport&gt;</code></pre>
  </div>
  </div>
  </p>