title: Fix odd DatePicker animation behaviour in SwiftUI form
body: <p>I'm getting some odd animation behaviour with DatePickers in a SwiftUI form. A picture is worth a thousand words, so I'm sure a video is worth a million words: <a href="https://imgur.com/a/UHXqXOh" rel="noreferrer">https://imgur.com/a/UHXqXOh</a></p>
  <p>I'm trying to get the date picker to expand and then collapse within the form, exactly like the behaviour when creating a new event in Calendar.app</p>
  <p>What is happening for me is:</p>
  <ol>
  <li>Any expanding item in a Section (other than the last one) will open normally, but when it closes the expanded part slides down and fades, instead of sliding up and fading.</li>
  <li>The last item in the section slides correctly but doesn't fade at all. It simply appears and then disappears at the start/end of the transition</li>
  </ol>
  <p>These behaviours only happen if there is a non-DatePicker element (e.g. Text, Slider) somewhere in the form (doesn't have to be in that particular section)</p>
  <p>Here's my ContentView:</p>
  <pre><code>struct ContentView: View {
      @State var date = Date()
      @State var isDateShown = false
      var body: some View {
              Form {
                  Section(header: Text(&quot;Title&quot;)) {
                      DatePicker(&quot;Test&quot;, selection:$date)
                      DatePicker(&quot;Test&quot;, selection:$date)
                      Text(&quot;Pick a date&quot;).onTapGesture {
                          withAnimation {
                              self.isDateShown.toggle()
                          }
                         
                      }
                      if(isDateShown) {
                          DatePicker(&quot;&quot;, selection: $date).datePickerStyle(WheelDatePickerStyle()).labelsHidden()
                      }
                      
                  }
                  Section(header: Text(&quot;hello&quot;)) {
                      Text(&quot;test&quot;)
                  }
          }
          
      }
  }
  </code></pre>
  <p>Happy to provide anything else required</p>