Kubernetes-commit: a68c57155e728b2782408cbab88ecee0444a4ba8
Kubernetes-commit: e7fbbe0e3c91f34836b999e695aa133503cfdae5
Kubernetes-commit: 817bc6954ca9af02013fd8f492f8ef865c217b0d
This change does three things: 1. use auditinternal for unit test in filter stage 2. add a seperate unit test for Audit-ID http header 3. add unit test for audit log backend Kubernetes-commit: c030026b544da2dd7ef7201019bdc0ac255c2d23