Pod propagation should disable the use of custom pod informer

[limhawjia]

PR #46 introduces a custom pod informer that transform pod objects before caching.

With support for pod federation, we need to ensure that this custom pod informer is disabled for certain pod subcontrollers to work properly, e.g. sync, status

[SOF3]

Should we just pass a separate informer for pruned pods instead of intrusively modifying the pod informer for all use cases that didn't want pruning?