Automatic merge from submit-queue (batch tested with PRs 57324, 56931, 57000, 57150, 56965). 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 YAMLDecoder Read behaviour

**What this PR does / why we need it**:

Makes YAMLDecoder adhere to the Read contract by returning the number of bytes
read.

**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 #56999

**Special notes for your reviewer**:

**Release note**:

```release-note
YAMLDecoder Read now returns the number of bytes read
```