Add explicit hub/tag overrides for Helm commands (#8475)
Add explicit hub/tag overrides for Helm commands (#8475)

Helm charts are no longer templated at release build time to contain the correct
default hub/tag but instead point to testing hub and latest tag.

Updated docs to instruct users to explicitly set the hub and tag while executing
Helm commands.
istio/istio.io,istio/istio.io,istio/istio.io,istio/istio.io,istio/istio.io,istio/istio.io,istio/istio.io