Automatic merge from submit-queue (batch tested with PRs 52831, 52764, 52763, 52673, 52558). 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>..
Allow updating objects with empty pending initializers list
**What this PR does / why we need it**: When updating an object, an empty pending list should be treated as a nil initializer. This PR fixes a bug which prevented this functionality and also adds a test which will ensure this functionality is preserved.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#52202
**Special notes for your reviewer**:
/cc @caesarxuchao
**Release note**:
```release-note
Fixes an initializer bug where update requests which had an empty pending initializers list were erroneously rejected.
```
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