Automatic merge from submit-queue (batch tested with PRs 68051, 68130, 67211, 68065, 68117). If you want to cherry-pick this change to another branch, please follow the instructions here: https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md.

Put fluentd back to host network

In the future we will want to monitor each system component that is deployed as a DaemonSet using only one instance of prometheus-to-sd (which will be deployed as a DaemonSet too), but for this we need all the system components to be part of host network. There is no port colision created with this change.
```release-note
Port 31337 will be used by fluentd
```