Automatic merge from submit-queue

Quote groups in deny log message

Helps distinguish cases where an external authenticator is incorrectly combining multiple groups into one.

Before:
> RBAC DENY: user "bob" groups [system:masters view system:authenticated] cannot "list" resource "pods" cluster-wide

After:
> RBAC DENY: user "bob" groups ["system:masters view" "system:authenticated"] cannot "list" resource "pods" cluster-wide