Hi MinAmung,
For Delivery tasks (for Package Delivery and for Quick Delivery tasks) this option can be changed in the advanced task options.
Default timout value can be managed for Managed Delivery Policies in the global setings (Settings -> Software -> Managed Delivery Settings). The "terminate after" setting (end task timout). Change it and it will be reflected on any new policies.
I suggest you to use MD policies for software delivery, or change "End task after" advanced setting manualy for each task.