Restart All Containers on Container Exits

This KEP proposes an extension to the container restart rules introduced in KEP-5307 to allow a container's exit to trigger a restart of the entire pod. This is part of the Pod / Container Restart roadmap planned earlier (see discussion). This "in-place" pod restart will terminate and then restart all of the pod's containers (including init and sidecar containers) while preserving the pod's sandbox, UID, network namespace, attached devices, and IP address. This provides a more efficient way to reset a pod's state compared to deleting and recreating the pod, which is particularly beneficial for workloads like AI/ML training, where rescheduling is costly.