Fix "Defect-MAGN-590.xml" that was mistakenly slowed down

The slight pause should have been introduced after all the commands are done playing back (i.e. ```PauseAfterPlaybackInMs```), not in between two commands (i.e. ```CommandIntervalInMs```). That ```500ms``` slowdown accumulates to slow down the whole test. We need a pause after the final update so that background worker has a chance to finish the evaluation.