[devkit] plugin.xml: add plugin@allow-bundled-update attribute

plugins/devkit/src/dom/IdeaPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2016 JetBrains s.r.o.
+ * Copyright 2000-2017 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,6 +56,9 @@ public interface IdeaPlugin extends DomElement {
   @NotNull
   GenericAttributeValue<Boolean> getUseIdeaClassloader();
 
+  @NotNull
+  GenericAttributeValue<Boolean> getAllowBundledUpdate();
+
   @NotNull
   @Stubbed
   GenericDomValue<String> getName();