Automatic merge from submit-queue (batch tested with PRs 51819, 51706, 51761, 51818, 51500)

fix kube-proxy panic because of nil sessionAffinityConfig

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

fix kube-proxy panic because of nil sessionAffinityConfig

**Which issue this PR fixes**: closes #51499 

**Special notes for your reviewer**:

I apology that this bug is introduced by #49850 :(

@thockin @smarterclayton @gnufied 

**Release note**:

```release-note
NONE
```