Automatic merge from submit-queue
Support HostAlias for HostNetwork Pods
**What this PR does / why we need it**: Currently, HostAlias does not support HostNetwork pods because historically, kubelet only manages hosts file for non-HostNetwork pods. With the recent change in https://github.com/kubernetes/kubernetes/pull/49140, kubelet now manages hosts file for all Pods, which enables HostAlias support also.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#48398
**Special notes for your reviewer**: might be easier to review commit-by-commit
**Release note**:
```release-note
HostAlias is now supported for both non-HostNetwork Pods and HostNetwork Pods.
```
@yujuhong @hongchaodeng @thockin
ef1b835220