Optionally caller-specified in CreateTask.
The task name.
The task name must have the following format:
* `PROJECT_ID` can contain letters ([A-Za-z]), numbers ([0-9]), hyphens (-), colons (:), or periods (.). For more information, see [Identifying projects](https://cloud.google.com/resource-manager/docs/creating-managing-projects#identifying_projects)
* `LOCATION_ID` is the canonical ID for the task's location. The list of available locations can be obtained by calling ListLocations. For more information, see https://cloud.google.com/about/locations/.
* `QUEUE_ID` can contain letters ([A-Za-z]), numbers ([0-9]), or hyphens (-). The maximum length is 100 characters.
* `TASK_ID` can contain only letters ([A-Za-z]), numbers ([0-9]), hyphens (-), or underscores (_). The maximum length is 500 characters.