max_retry_duration specifies the time limit for retrying a
failed task, measured from when the task was first attempted. Once
max_retry_duration time has passed and the task has been attempted
max_attempts times, no further attempts will be made and the task will be
deleted. If zero, then the task age is unlimited. If unspecified when the
queue is created, Cloud Tasks will pick the default.
will be truncated to the nearest second. This field has the same meaning
as task_age_limit in