Automatic merge from submit-queue (batch tested with PRs 59365, 60446, 60448, 55019, 60431). 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>.

Use feature-gates command line for kube-proxy

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

Avoid throwing `featureGates:` into the kube-proxy yaml, since it's
not in the right format. It should be

```
    featureGates:
      AllAlpha: true
```

Since FEATURES_GATES is set to `AllAlpha=true`, we can't just throw that
into the yaml file. Just pass along FEATURES_GATES in the command line
instead just like we do for all other services

**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 #60426

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```