Open extension dialog to Installed tab if updates are available

src/extensibility/ExtensionManagerDialog.js

@@ -293,8 +293,14 @@ define(function (require, exports, module) {
                 });
             });
 
-            // Show the first tab
-            $dlg.find(".nav-tabs a:first").tab("show");
+            // Open dialog to Installed tab if extension updates are available
+            if ($("#toolbar-extension-manager").hasClass('updatesAvailable')) {
+                $dlg.find(".nav-tabs a.installed").tab("show");
+            }
+            // Otherwise show the first tab
+            else {
+                $dlg.find(".nav-tabs a:first").tab("show");
+            }
         });
 
         // Handle the install button.