CupertinoPicker example does not select initial value when dismissed #110732

Steps to reproduce:

1. go to https://api.flutter.dev/flutter/cupertino/CupertinoPicker-class.html
2. open the picker in the dartpad and select a value other than Apple, e.g. Orange
3. dismiss the picker and observe that the button has updated to the selected value
4. open the picker again and observe that the initially selected value is Apple
5. dismiss the picker and observe that the button does not update to Apple

Expected behavior:
the button should be updated to the selected value when the picker is dismissed