Add at-since TODO to Javadoc

Co-Authored-By: NOleg Nenashev <o.v.nenashev@gmail.com>

core/src/main/java/hudson/model/Descriptor.java

@@ -838,6 +838,7 @@ public abstract class Descriptor<T extends Describable<T>> implements Saveable,
      * Override to return something different if appropriate. The only currently supported alternative return value is {@link Jenkins#MANAGE}.
      *
      * @return Permission required to configure this descriptor.
+     * @since TODO
      */
     public @Nonnull
     Permission getRequiredPermission() {

core/src/main/java/jenkins/model/Jenkins.java

@@ -5251,6 +5251,7 @@ public class Jenkins extends AbstractCIBase implements DirectlyModifiableTopLeve
      *
      * As an experimental feature, making the manage permission able to be disabled by default (keep as ADMINISTER), can
      * be enabled with "jenkins.security.ManagePermission" system property.
+     * @since TODO
      */
     @Restricted(Beta.class)
     public static final Permission MANAGE = new Permission(PERMISSIONS, "Manage",