The ConceptServiceImpl.updateConceptIndexes() method attempts to prevent the task from being scheduled if it already scheduled. We should make this an api method in the SchedulerService so that the pattern doesn't have to be duplicated by other services/devs/modules.
Create method SchedulerService.scheduleIfNotExists(TaskDefinition)
Create a unit test to verify this method is working.
ABKTODO: this whole pattern should be moved into the scheduler, providing a call like scheduleThisIfNotRunning()