Pulpcore: rbac permissions incorrectly assigned in tasks that create objects

A flaw was found in the Pulp package. When a role-based access control (RBAC) object in Pulp is set to assign permissions on its creation, it uses the `AutoAddObjPermsMixin` (typically the add_roles_for_object_creator method). This method finds the object creator by checking the current authenticated user. For objects that are created within a task, this current user is set by the first user with any permissions on the task object. This means the oldest user with model/domain-level task permissions will always be set as the current user of a task, even if they didn't dispatch the task. Therefore, all objects created in tasks will have their permissions assigned to this oldest user, and the creating user will receive nothing.