Fix cache issue when billing cache is enabled

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/MetadataServiceImpl.java

@@ -110,6 +110,7 @@ public class MetadataServiceImpl implements MetadataService {
         RequestValidationUtil.validateMetadata(metadata);
         try {
             Metadata createdMetadata = DeviceMgtAPIUtils.getMetadataManagementService().createMetadata(metadata);
+            DeviceManagerUtil.removeBillingCache();
             return Response.status(Response.Status.CREATED).entity(createdMetadata).build();
         } catch (MetadataKeyAlreadyExistsException e) {
             String msg = "Metadata entry metaKey:" + metadata.getMetaKey() + " is already exist.";

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/util/DeviceManagerUtil.java

@@ -701,7 +701,8 @@ public final class DeviceManagerUtil {
      */
     public static void removeBillingCache() {
         CacheManager manager = getCacheManager();
-        manager.removeCache(DeviceManagementConstants.BILLING_CACHE);
+        Cache cache = manager.getCache(DeviceManagementConstants.BILLING_CACHE);
+        cache.removeAll();
     }
 
     /**