Added a method to get the device count based on app os type with group

components/device-mgt/io.entgra.device.mgt.core.device.mgt.core/src/main/java/io/entgra/device/mgt/core/device/mgt/core/service/GroupManagementProviderServiceImpl.java

@@ -77,6 +77,7 @@ public class GroupManagementProviderServiceImpl implements GroupManagementProvid
 
     private final GroupDAO groupDAO;
     private final DeviceDAO deviceDAO;
+
     /**
      * Set groupDAO from GroupManagementDAOFactory when class instantiate.
      */