Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
improve test: verify kubelet.config.Restore only happen once
**What this PR does / why we need it**:
This patch is to add additional test coverage of pod config restore,
it verifies that restore can only happen once.
in the second restore attempt, we should expect no error and no channel update.
**Which issue(s) this PR fixes**:
this is a test improvement based on test been added at https://github.com/kubernetes/kubernetes/pull/63553
**Special notes for your reviewer**:
**Release note**:
```release-note
None
```
/sig node
/cc @rphillips @jiayingz @vikaschoudhary16 @anfernee @Random-Liu @dchen1107 @derekwaynecarr
@vishh @yujuhong @tallclair
c6e0a225f9