Update fat-flow configuration in schema

Define source-prefix and destination-prefix options in FatFlow
configuration

Partial-Bug: #1752618
(cherry picked from commit 25be0e4)

Change-Id: I54fd875a9eb0715b5bbe8edceb8ea658f4bda1ba

schema/vnc_cfg.xsd

@@ -1886,9 +1886,13 @@ targetNamespace="http://www.contrailsystems.com/2012/VNC-CONFIG/0">
     <xsd:all>
         <xsd:element name="protocol" type="xsd:string"/>
         <xsd:element name="port" type="xsd:integer"/>
-        <xsd:element name="ignore-address" type="FatFlowIgnoreAddressType"/>
+        <xsd:element name="ignore-address" type="FatFlowIgnoreAddressType"
              required='optional'
              description='Address ignored while creating flows, from the perspective of packets egressing the VM. For packets originated by VM, source and destination indicate the corresponding IPs in the packet. For packets coming from remote source, source indicates destination IP of the packet is ignored and destination indicates source IP of the packet is ignored.'/>
+        <xsd:element name="source-prefix" type="SubnetType" required='optional'
+            description='For packets originated from VM source-prefix is applied to source IP of the packet. For packets coming to VM, source-prefix is applied to destination IP of the packet' />
+        <xsd:element name="destination-prefix" type="SubnetType" required='optional'
+            description='For packets originated from VM destination-prefix is applied to destination IP of the packet. For packets coming to VM, destination-prefix is applied to source IP of the packet' />
     </xsd:all>
 </xsd:complexType>