Revert "dropdown: Shuffle accessible roles around"

This reverts commit 5ec0b07baf.

Unfortunately, this makes it so that the focus ends up on
the 'generic' accessible, not the one with the label, and
orca remains quiet.

gtk/gtkdropdown.c

@@ -695,10 +695,7 @@ setup_item (GtkSignalListItemFactory *factory,
   label = gtk_label_new (NULL);
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
   gtk_box_append (GTK_BOX (box), label);
-  icon = g_object_new (GTK_TYPE_IMAGE,
-                       "icon-name", "object-select-symbolic",
-                       "accessible-role", GTK_ACCESSIBLE_ROLE_NONE,
-                       NULL);
+  icon = gtk_image_new_from_icon_name ("object-select-symbolic");
   gtk_box_append (GTK_BOX (box), icon);
   gtk_list_item_set_child (list_item, box);
 }

gtk/ui/gtkdropdown.ui

@@ -3,7 +3,6 @@
   <template class="GtkDropDown" parent="GtkWidget">
     <child>
       <object class="GtkToggleButton" id="button">
-        <property name="accessible-role">generic</property>
         <signal name="toggled" handler="button_toggled"/>
         <child>
           <object class="GtkBox">