fix(dex): change to clusterrole for crd creation

[Synehan]

Q	A
Bug fix?	yes
New feature?	no
API breaks?	no
Deprecations?	no
Related tickets	none
License	Apache 2.0

What's in this PR?

Allows Dex to create CRD through a clusterrole

Why?

Dex creates its own CRD when deployed, and as CRD are ClusterScoped resources, you need a clusterrole / clusterrolebinding.
Else, dex log the following message:

 time="2020-12-18T08:40:24Z" level=error msg="creating custom resource devicetokens.dex.coreos.com: POST https://[]:443/apis/apiextensions.k8s.io/v1beta1/customresourcedefinitions Forbidden: response from server \"{\"kind\":\"Status\",\"apiVersion\":\"v1\",\"metadata\":{},\"status\":\"Failure\",\"message\":\"customresourcedefinitions.apiextensions.k8s.io is forbidden: User \\\"system:serviceaccount:infra-dex:dex\\\" cannot create resource \\\"customresourcedefinitions\\\" in API group \\\"apiextensions.k8s.io\\\" at the cluster scope\",\"reason\":\"Forbidden\",\"details\":{\"group\":\"apiextensions.k8s.io\",\"kind\":\"customresourcedefinitions\"},\"code\":403}\""

Checklist

• Code meets the Developer Guide
• User guide and development docs updated (if needed)
• Related Helm chart(s) updated (if needed)