[Sample, Component] XGBoost sample test flakiness

[numerology]

Currently we're observing ongoing flakiness of XGBoost sample. A brief investigation shows that it's highly likely caused by the fact that we currently do not have a way to correctly specify the new GCP dataproc_delete_cluster as exit handler component, then argo cannot determine the execution order properly, resulting in race condition.

What do we need:
This should be fixed by modifying the corrensponding component yaml spec. For example, the generated ContainerOp should have is_exit_handler = True