Automatic merge from submit-queue
Improve description for --masquerade-all and --cluster-cidr flags
**What this PR does / why we need it**:
Improves the help text for the kube-proxy's `--masquerade-all` and `--cluster-cidr` flags, which previously were vague and confusing.
Fixes https://github.com/kubernetes/kubernetes/issues/47213
```release-note
NONE
```