Read status message when command been copied (#8289)

Author: lyndaidaii

src/NuGetGallery/Views/Packages/DisplayPackage.cshtml

@@ -150,7 +150,7 @@
                 <div class="copy-button">
                     <button id="@packageManager.Id-button" class="btn btn-default btn-warning" type="button"
                             data-toggle="popover" data-placement="bottom" data-content="Copied."
-                            aria-label="@packageManager.CopyLabel">
+                            aria-label="@packageManager.CopyLabel" aria-live="polite" role="status">
                         <span class="ms-Icon ms-Icon--Copy" aria-hidden="true"></span>
                     </button>
                 </div>