title: Listbox doesn't detect selected item
body: <p>I have the following listbox:</p>
  
  <pre><code>&lt;ListBox ItemsSource="{Binding AvailableTemplates}" Style="{DynamicResource SearchListBoxStyle}" SelectedItem="{Binding SelectedTemplate, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"&gt;
    &lt;ListBox.ItemTemplate&gt;
      &lt;DataTemplate&gt;
        &lt;RadioButton Content="{Binding}" GroupName="group" /&gt;
      &lt;/DataTemplate&gt;
    &lt;/ListBox.ItemTemplate&gt;
  &lt;/ListBox&gt;
  </code></pre>
  
  <p>this doesn't detect as selected item changed if i select on the radiobutton. It only detects if i click under the radio button on the listbox row. Any ideeas how to amend to detect as selected item changed when clicking on the radio button?</p>