Use explicit region variable instead of data source

[bobbyiliev]

Replacing data.google_client_config.current.region with var.region in the helm_values to fix empty region issue in multi-region GCP projects.

[kay-kim]

QQ: When defining the kubernetes and helm providers, we refer to the google_client_config:
token = data.google_client_config.current.access_token.
In our docs, I can have them declare data "google_client_config" "current" {} at the same time, but wanted to double check that this is okay. It seems preferred since we have them declare it at the same time as when they refer to it. But, wasn't sure if there were any gotchas.