title: Ion-select does not show selected option when value is an object type
body: <p><strong>I am binding an object to the value property of select-option.</strong></p>
  <pre><code> &lt;ion-item&gt;
      &lt;ion-label&gt;Choose&lt;/ion-label&gt;
      &lt;ion-select [value]=&quot;{key:'abc',value:'ABC'}&quot;&gt;
        &lt;ion-select-option value=&quot;{key:'abc',value:'ABC'}&quot;&gt;ABC&lt;/ion-select-option&gt;
        &lt;ion-select-option value=&quot;{key:'pqr',value:'PQR'}&quot;&gt;PQR&lt;/ion-select-option&gt;
        &lt;ion-select-option value=&quot;{key:'xyz',value:'XYZ'}&quot;&gt;XYZ&lt;/ion-select-option&gt;
      &lt;/ion-select&gt;
    &lt;/ion-item&gt;
  </code></pre>
  <p><strong>When popup opens it does not show the selected value.</strong></p>
  <p><a href="https://i.stack.imgur.com/xPn2D.png" rel="nofollow noreferrer">Click here to view the image</a></p>