Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Update GCP fluentd configmap for COS audit logging on GKE node
**What this PR does / why we need it**:
This PR adds a placeholder in fluentd configmap for COS audit logging on GKE node.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
**Special notes for your reviewer**:
NONE
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>..
[fluentd-gcp addon] Update Stackdriver plugin to version 0.6.7
A new gem among all fixes Java logging severity parsing and string timestamp parsing
Also sync the buffer size with the gem guidelines, making it 1M instead of 2M.
/cc @igorpeshansky