title: onDismiss prop for modals using react native navigation
body: <p>I've seen that there is an <code>onDismiss</code> prop for the <code>Modal</code> <a href="https://reactnative.dev/docs/modal#ondismiss-ios" rel="nofollow noreferrer">Core Component of React Native</a>.</p>
  <p>I haven't tested this, but assume it is called after the modal closing animation has completed.</p>
  <p>I am wondering if there is a similar prop for stack navigators using <code>screenOptions={{ presentation: 'modal' }}</code>?</p>