remvoing restriction that prevents activity count to be returned when if-modified-since header is present

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

@@ -298,11 +298,11 @@ public class ActivityProviderServiceImpl implements ActivityInfoProviderService
                 }
                 activityList.setList(activities);
                 activityList.setCount(count);
-                if (activities == null || activities.size() == 0) {
+//                if (activities == null || activities.size() == 0) {
-                    if (isIfModifiedSinceSet) {
+//                    if (isIfModifiedSinceSet) {
-                        return Response.notModified().build();
+//                        return Response.notModified().build();
-                    }
+//                    }
-                }
+//                }
                 return Response.ok().entity(activityList).build();
             } catch (OperationManagementException e) {
                 String msg