add accelerate network for update (#1318)

* add accelerate network for update

* update return type and javadoc

* update javadoc due to update limitation

* udpate javadoc

* fix typo

Author: ChenTanyi

azure-mgmt-network/src/main/java/com/microsoft/azure/management/network/NetworkInterface.java

@@ -515,14 +515,25 @@ interface WithIPConfiguration {
         }
 
         /**
-         * The stage of the network interface definition allowing to disable accelerated networking.
+         * The stage of the network interface definition allowing to specify accelerated networking.
          */
         interface WithAcceleratedNetworking {
+            /**
+             * Enables accelerated networking.
+             * <p>
+             * Note that additional steps need to be taken in the virtual machine itself for the virtual machine associated with this network interface to be able to
+             * take advantage of accelerated networking. This feature might not be available in some regions, virtual machine sizes, or operating system versions.
+             * It cannot be enabled if it has already been attached to a running virtual machine.
+             * @return the next stage of the update
+             */
+            Update withAcceleratedNetworking();
+
             /**
              * Disables accelerated networking.
              * @return the next stage of the update
              */
-            Update withoutAcceleratedNetworking();        }
+            Update withoutAcceleratedNetworking();
+        }
 
         /**
          * The stage of the network interface update allowing to associate it with a load balancer.