Fix accessibility issue - role required when aria-expanded attribute is used (#9445)

* add button role when using aria-expanded attribute

* add form role when using aria-expanded attribute

* remove redundant and incorrect use of aria-expanded attribute

Author: keylime-unicorn

src/NuGetGallery/App_Code/ViewHelpers.cshtml

@@ -577,8 +577,8 @@ var hlp = new AccordionHelper(name, formModelStatePrefix, expanded, page);
     </div>
     if (!disabled)
     {
-        <div class="panel panel-default panel-collapse collapse @(expanded ? "in" : string.Empty)"
-                aria-expanded="@(expanded ? "true" : "false")" id="@id-container">
+        <div aria-controls="panel-body" class="panel panel-default panel-collapse collapse @(expanded ? "in" : string.Empty)"
+                id="@id-container">
             <div class="panel-body">
                 @content(MvcHtmlString.Empty)
             </div>