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>.
fix package name error
1.priority admission file got wrong package name
2.PriorityPlugin struct should not be public as well as its construct function.
this patch fix this.
**What this PR does / why we need it**:
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
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>.
Critical pod priorityClass addition
**What this PR does / why we need it**:
@bsalamat - Apologies for the delay. This PR is to ensure that all pods with priorityClassName `system-node-critical` and `system-cluster-critical` will be critical pods while preserving backwards compatibility.
**Special notes for your reviewer**:
- Moved some constants and other data structures to scheduler/api/types.go where other constants are present.
- An automatic assignment of critical priorities to pods based on critical pod annotation for backwards compatibility including some unit tests.
xref: https://github.com/kubernetes/kubernetes/issues/57471
**Release note**:
```release-note
Critical pods to use priorityClasses.
```
Automatic merge from submit-queue (batch tested with PRs 54761, 54748, 53991, 54485, 46951). 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>.
admission: unify plugin constructors
It's common in Go to return the actual object in constructors, not **one interface**
it implements. This allows us to implement multiple interfaces, but only have
one constructor. As having private types in constructors, we export all plugin structs, of course with private fields.
Note: super interfaces do not work if there are overlapping methods.
