Automatic merge from submit-queue

Move fluentd DS config to configmap

This is the logical continuation of https://github.com/kubernetes/kubernetes/pull/41998. This PR makes fluentd-gcp DaemonSet use the new image configured using ConfigMap.

This PR doesn't change the way fluentd-gcp works in case master is not registered, that'll be fixed in a separate PR

CC @ixdy @timstclair @igorpeshansky @qingling128 @dhrupadb

**Release note:**

```release-note
Fluentd-gcp containers spawned by DaemonSet are now configured using ConfigMap
```