What would you like to be added:
Expose the init containers start/terminated timestamps

Why is this needed:
We are trying to monitor the container start latencies and observed that kube_pod_container_state_started and kube_pod_container_status_last_terminated_timestamp does not provide information on the init containers.

Describe the solution you'd like
Expose the epoch time stamps of the init-containers creation and termination events

Additional context