Automatic merge from submit-queue (batch tested with PRs 54419, 53545). 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>.
change alpha-endpoint-reconciler-type argument to endpoint-reconciler-type
**What this PR does / why we need it**: Tweaks the endpoint reconciler argument to remove 'alpha', because according to this [comment](https://github.com/kubernetes/kubernetes/pull/50984#discussion_r146290402) we are preferring to document the flags.
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
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