Fix CalcAddins example

was broken with 70f56bc2 "java: reduce scope,
make member classes private"

Change-Id: I84a3fafbfdddf6bb04ab7787d344bf50ffd22994

odk/examples/java/Spreadsheet/CalcAddins.java

@@ -60,7 +60,7 @@ public class CalcAddins {
  * of the service description. It implements the needed interfaces.
  * @implements XCalcAddins, XAddIn, XServiceName, XServiceInfo, XTypeProvider
  */
-    private static class _CalcAddins extends WeakBase implements
+    public static class _CalcAddins extends WeakBase implements
                                             XCalcAddins,
                                             XAddIn,
                                             XServiceName,