In the case of Static Mirroring Case, need to set Destination network

with  Mirroring flag so that insted of  choosing VRF NH for VXLAN
will choose composite Interface NH.
partial-bug: #1592049

Change-Id: Idd6055905a0e9b5ab732f2aa45ccb492765d8b9c

src/schema/vnc_cfg.xsd

@@ -1174,6 +1174,9 @@ targetNamespace="http://www.contrailsystems.com/2012/VNC-CONFIG/0">
         <!-- Enable or disable unicast RPF for virtual-network -->
         <xsd:element name='rpf' type='RpfModeType' required='optional'
              description='Flag used to diable Reverse Path Forwarding(RPF) check for this network'/>
+         <!-- Enable or disable Mirroring for virtual-network -->
+         <xsd:element name='mirror-destination' type="xsd:boolean" default="false" required='optional'
+             description='Flag to mark the virtual network as mirror destination network'/>
     </xsd:all>
 </xsd:complexType>