title: SwiftUI Picker in Form does not show checkmark
body: <p>I have a Picker embedded in Form, however I can't get it working that it shows a checkmark and the selected value in the form.</p>
  
  <pre><code>NavigationView {
      Form {
          Section {
                  Picker(selection: $currencyCode, label: Text("Currency")) {
                      ForEach(0 ..&lt; codes.count) {
                          Text(self.codes[$0]).tag($0)
                      }
                  }
              }
      }
  }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/IE5u7.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/IE5u7.gif" alt="No checkmark and no selected value"></a></p>