Helm - configurable kube-rbac-proxy container image

[TomHellier]

Describe the feature you'd like to have. It should be possible to configure the kube-rbac-proxy containers image, similarly to how the manager container image can be configured. 

What is the value to the end user? (why is it a priority?) I mirror docker images to an internal registry so need to be able to change these settings. 

How will we know we have a good solution? (acceptance criteria) You can configure the kube-rbac-proxy image 

Additional context