Enable Overriding Poll Interval for Kubernetes Jobs

[richardatphilo]

Description

This change simply updates the KubernetesJobTask class to enable setting a poll_interval attribute or property. This allows subclasses to change how often the task polls the Kubernetes server for job status.

Motivation and Context

For long-running tasks, polling Kubernetes every 5 seconds for completion wastes resources. If a task author knows that a task is expected to run for many minutes, they can specify a longer interval to poll less frequently.

How I Tested It

I set up a test task by subclassing KubernetesJobTask and enabled debug logging. When poll_interval is not re-defined on the child class, the task polls every 5 seconds for completion. When adding a class attribute for poll_interval to the subclass, the task polled according to the new value.

[dlstadther]

I agree with this change.

In the event someone was overriding the value of __POLL_TIME, this would break. But given that class var is denoted as "private", i think this is a fine change.

Thanks!