Automatic merge from submit-queue
[GCE kube-up] Add a warning for kube-proxy DaemonSet option
**What this PR does / why we need it**:
Add a warning for kube-proxy DaemonSet option for GCE kube-up so that user will be aware of the risks.
Ref: https://github.com/kubernetes/kubernetes/issues/23225
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #NONE
**Special notes for your reviewer**:
/assign @bowei
**Release note**:
```release-note
NONE
```
Deprecation Notice: This directory has entered maintenance mode and will not be accepting new providers. Please submit new automation deployments to kube-deploy. Deployments in this directory will continue to be maintained and supported at their current level of support.
The scripts and data in this directory automate creation and configuration of a Kubernetes cluster, including networking, DNS, nodes, and master components.