Upgrade device management core version

pom.xml

@@ -1529,7 +1529,7 @@
         <carbon.governance.version>4.7.23</carbon.governance.version>
 
         <!-- Carbon Device Management-->
-        <carbon.device.mgt.version>3.1.17</carbon.device.mgt.version>
+        <carbon.device.mgt.version>3.1.18</carbon.device.mgt.version>
         <carbon.device.mgt.version.range>[3.1.0, 4.0.0)</carbon.device.mgt.version.range>
 
         <!-- IOT Device Management -->