Fix build failure

components/mobile-plugins/android-plugin/org.wso2.carbon.device.mgt.mobile.android.api/src/test/java/org/wso2/carbon/mdm/services/android/mocks/DeviceManagementProviderServiceMock.java

@@ -751,4 +751,7 @@ public class DeviceManagementProviderServiceMock implements DeviceManagementProv
         return false;
     }
 
+    @Override public List<Device> getDeviceByIdList(List<String> list) throws DeviceManagementException {
+        return null;
+    }
 }