Refactor whitelabel update api method name to update from create

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

@@ -192,7 +192,7 @@ public interface WhiteLabelService {
                                     "\n Server error occurred while creating white label theme.",
                             response = ErrorResponse.class)
             })
-    Response createWhiteLabelTheme(WhiteLabelThemeCreateRequest whiteLabelThemeCreateRequest);
+    Response updateWhiteLabelTheme(WhiteLabelThemeCreateRequest whiteLabelThemeCreateRequest);
 
     @GET
     @ApiOperation(

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

@@ -88,7 +88,7 @@ public class WhiteLabelServiceImpl implements WhiteLabelService {
 
     @PUT
     @Override
-    public Response createWhiteLabelTheme(WhiteLabelThemeCreateRequest whiteLabelThemeCreateRequest) {
+    public Response updateWhiteLabelTheme(WhiteLabelThemeCreateRequest whiteLabelThemeCreateRequest) {
         RequestValidationUtil.validateWhiteLabelTheme(whiteLabelThemeCreateRequest);
         try {
             WhiteLabelTheme createdWhiteLabelTheme = DeviceMgtAPIUtils.getWhiteLabelManagementService().updateWhiteLabelTheme(whiteLabelThemeCreateRequest);