Automatic merge from submit-queue (batch tested with PRs 66175, 66324, 65828, 65901, 66350). 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>.
Hpa improv refactor replica calc test
**What this PR does / why we need it**: prepareTestClient generates 4 fake clients, using replicaCalcTestCase object. This PR extracts a separate helper for generating each fake independently.
**Which issue(s) this PR fixes**
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
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