fix bugs in DatabaseArchiver.determineStartTime(). Change-Id: I2a7a71bcf7bdbc5ea786d949631b45342675ce1f Former-commit-id: 6e45fc4f0eb15409a20be99c02b2ac43c8ed842e
Former-commit-id: 64fa9254b946eae7e61bbc3f513b7c3696c4f54f