Samza onTimer method triggering before init

If you create a samza job with an onTimer method, TimerRegistry registers the timer before the container is running. This leads to an edge case where if the initial `registerTimer` delay is too small, the onTimer function will never get called (this can mean you never get to schedule subsequent timers if your onTimer function periodically schedules it's next call).

I ran into this when setting my timer to schedule onTimer events every 250 milliseconds. One temporary workaround for this is to make the registerTimer function have a high initial delay (e.g. 10 seconds).