Fix test case failures

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

@@ -152,12 +152,7 @@ public class DeviceManagementProviderServiceMock implements DeviceManagementProv
     }
 
     @Override
-    public PaginationResult getAllDevicesBillings(PaginationRequest paginationRequest, int i, String s, Timestamp timestamp, Timestamp timestamp1, boolean b) throws DeviceManagementException {
+    public PaginationResult createBillingFile(int i, String s, Timestamp timestamp, Timestamp timestamp1) throws DeviceManagementException {
-        return null;
-    }
-
-    @Override
-    public PaginationResult createBillingFile(int i, String s, Timestamp timestamp, Timestamp timestamp1, boolean b) throws DeviceManagementException {
         return null;
     }