Automatic merge from submit-queue

plugin/pkg: add ericchiang to owners for OpenID Connect plugins

On the CoreOS side I'm taking over these components.

@erictune has suggested `pkg/registry/{cluster}role{binding}s/OWNERS` as well but I'd feel more comfortable as a reviewer for those specific parts of RBAC for a couple more cycles since @liggitt and @deads2k have had way more experience in the registry code.

Beyond that the only existing OWNERS files for auth are `pkg/auth/OWNERS` and `plugin/pkg/auth/OWNERS` both of which include @liggitt and @erictune. There's also nothing in the `plugin/pkg/client` path. I'm a little unclear on the implications for future PRs that are assigned to me (e.g. webhook or RBAC reviews).

cc @kubernetes/sig-auth