TimerServiceImpl should clone the ScheduleExpression from the user input

ScheduleExpression can be modified after being submitted to timer service to create a calendar timer. So ejb3 timer service should clone the schedule expression from the user input. We should only clone it when necessary, i.e., only when user invokes the timer service create methods to create calendar timer, not for internally created calendar timer.

The tck test failure:

        [TEST FAILED] testName=allTZ Failed with EJBException caused by 
java.lang.RuntimeException: Check TZ in schedule: year=5000 month=* dayOfMonth=* dayOfWeek=* hour=0 minute=0 second=0 start=null end=null timezone=Africa/Harare

  Expecting EUROPE/ANDORRA, but actual AFRICA/HARARE
    at com.sun.ts.tests.ejb30.common.helper.Helper.assertEquals(Helper.java:89)
    at com.sun.ts.tests.ejb32.lite.timer.schedule.tz.TZScheduleBareBean.verifyTZ(TZScheduleBareBean.java:112)
    at com.sun.ts.tests.ejb32.lite.timer.schedule.tz.TZScheduleBareBean.allTZ(TZScheduleBareBean.java:85)

It was caused by recent 2 refactoring fixes, combined: