### What happened?

Today the function `getFinishTimeFromContainers` (pkg/controller/job/backoff_utils.go) only account for the regular containers finish time,
presumably assuming that init containers have completed before before.
However, with the sidecar (restartable init) containers, sidecar containers will always finish later than
regular containers. And those needs to be accounted for the calculation.

/kind bug

### What did you expect to happen?

The sidecar finish time will be accounted when calculating the job's finish time.

### How can we reproduce it (as minimally and precisely as possible)?

Sidecar container with prolonged termination logic on a job will result in incorrect finish time reporting.

### Anything else we need to know?

/sig apps
/priority backlog
KEP: https://github.com/kubernetes/enhancements/issues/753
[Sidecar Containers] Sidecar containers finish time needs to be accounted for in job controller
This is a GitHub Issue
repo:kubernetes
owner:kubernetes
Title : [Sidecar Containers] Sidecar containers finish time needs to be accounted for in job controller
Issue date:

--- start body ---
### What happened?

Today the function `getFinishTimeFromContainers` (pkg/controller/job/backoff_utils.go) only account for the regular containers finish time,
presumably assuming that init containers have completed before before.
However, with the sidecar (restartable init) containers, sidecar containers will always finish later than
regular containers. And those needs to be accounted for the calculation.

/kind bug

### What did you expect to happen?

The sidecar finish time will be accounted when calculating the job's finish time.

### How can we reproduce it (as minimally and precisely as possible)?

Sidecar container with prolonged termination logic on a job will result in incorrect finish time reporting.

### Anything else we need to know?

/sig apps
/priority backlog
KEP: https://github.com/kubernetes/enhancements/issues/753
--- end body ---
