Fix buttons a11y label for close and share button for image vc

Image View Controller buttons both close and share don't have correct
a11y label. This will add the localised label

iOS/Article/ImageViewController.swift

@@ -29,6 +29,8 @@ class ImageViewController: UIViewController {
         super.viewDidLoad()
 		
 		closeButton.imageView?.contentMode = .scaleAspectFit
+		closeButton.accessibilityLabel = NSLocalizedString("Close", comment: "Close")
+		shareButton.accessibilityLabel = NSLocalizedString("Share", comment: "Share")
 		
         imageScrollView.setup()
         imageScrollView.imageScrollViewDelegate = self