A company is seeking to streamline the setup of ECS (Elastic Container Service) clusters by leveraging CloudFormation templates. This automated process has been functional for some time. However, after the development team creates the necessary task definitions and assigns appropriate IAM roles to the tasks, they notice that the ECS tasks are not utilizing the permissions specified in those roles.

What specific ECS configuration setting needs to be specified in the /etc/ecs/ecs.config file to ensure that ECS tasks can properly use the assigned IAM roles?