Update Default Labels Used by Kiali

This issue is being opened as a result of the findings from this spike.

Since Istio enabled workloads automatically get injected with app.kubernetes.io/name and app.kubernetes.io/version it makes more sense to simply have Kiali look to those labels by default. The values should still be overridable so users can continue to use app and version if needed or any other labels for that matter.

Additionally, changes made to the umbrella template to add in the variables for Kiali should be rolled back as they are no longer needed.