Creation still in progress fixups

This should help with the recent increase in `Plines::JobBatch::CreationInStillInProgressError` errors we've been getting.  It won't cause the underlying problem causing the increase but will make it a bit less common (since 6 hours was too long of a timeout to begin with) and will log the reason the job batch creation got aborted, helping us to better understand the root cause.
Since this public might it be better to leave the default at 6 hours and expose a configuration value for overrides instead?