title: XML Data binding, how to get callback parameter
body: <p>This is the callback that I used:</p>
  <pre><code>var onSelectionChanged: (Boolean) -&gt; Unit = {}
  </code></pre>
  <p>My databinding XML syntax is wrong, and unfortunately it doesn't compiled,
  How to get the Boolean invocation result of the callback</p>
  <pre><code>   &lt;.......SwitchStrip
              android:layout_height=&quot;wrap_content&quot;
              android:layout_width=&quot;wrap_content&quot;
              app:stripText=&quot;@string/strip_text&quot;
              app:onSelectionChanged=&quot;@{() -&gt; viewModel.updateResult(callbackResult)}&quot; /&gt;
  </code></pre>