title: UIAccessibilityElement `accessibilityCustomActions` not working properly
body: <p>I have created an instance of <code>UIAccessibilityElement</code> in order to provide a set of custom actions together with some additional information (i.e. <code>accessibilityLabel</code> + <code>accessibilityHint</code>)</p>
  
  <p>The problem is that VoiceOver doesn't announce the existence of custom actions. They are there, they work, but don't get announced. Also, custom actions' hint is not being announced as well.</p>
  
  <p>Any ideas?</p>
  
  <p>Code to generate the element is below:</p>
  
  <pre class="lang-swift prettyprint-override"><code>private lazy var accessibilityOverviewElement: UIAccessibilityElement = {
      let element = UIAccessibilityElement(accessibilityContainer: self)
      element.accessibilityLabel = viewModel.accessibilityOverviewTitle
      element.accessibilityHint = viewModel.accessibilityOverviewHint
      element.isAccessibilityElement = true
  
      let close = UIAccessibilityCustomAction(
          name: viewModel.accessibilityCloseActionTitle,
          target: self,
          selector: #selector(self.accessibilityDidClose))
      close.accessibilityHint = viewModel.accessibilityCloseActionHint
  
      let expand = UIAccessibilityCustomAction(
          name: viewModel.accessibilityExpandActionTitle,
          target: self,
          selector: #selector(self.accessibilityDidExpand))
      expand.accessibilityHint = viewModel.accessibilityExpandActionHint
  
      element.accessibilityCustomActions = [close, expand]
      return element
  }()
  </code></pre>
  
  <p>I compute the element's frame in <code>viewDidLayoutSubviews()</code></p>
  
  <pre class="lang-swift prettyprint-override"><code>override func viewDidLayoutSubviews() {
      super.viewDidLayoutSubviews()
      var frame = view.bounds
      frame.size.height = SleepAidMinifiedPlayerViewController.defaultHeight
      accessibilityOverviewElement.accessibilityFrameInContainerSpace = frame
  }
  </code></pre>
  
  <p>Finally, I need to be able to enable/disable accessibility since this view controller slides from the bottom and hides, but it's not completely removed from the view hierarchy (so VoiceOver still focuses on its elements)</p>
  
  <pre class="lang-swift prettyprint-override"><code>func setAccessibility(enabled isEnabled: Bool) {
      view.accessibilityElements = isEnabled ? [accessibilityOverviewElement, /* + other accessible elements*/].compactMap { $0 } : []
  }
  </code></pre>
  
  <p>Thanks!</p>