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>. juju: Add audit support to kubernetes-master charm **What this PR does / why we need it**: This PR adds audit configuration support to the kubernetes-master charm. Specifically, it enables audit logging by default, and adds two new config options: `audit-policy` and `audit-webhook-config`. **Release note**: ```release-note NONE ```