Make all configurations available in helm-based deployment.

As discussion on slack, to meet with simplicity and flexibility, it's better to extend the current limited configurations (environment variables) in helm templates/files.

Due to we have plenty of environment variables passed from helm or ansible into containers, it's better to have a consistent/single place to doc all variables and even automation on updating templates.

This will also help us to provide the doc for all values in helm.

Related issue: https://github.com/apache/incubator-openwhisk/issues/3645

No specific files are named. Start by reviewing the current Helm templates/files and the environment variables passed from Helm or Ansible, then compare the related issue 3645; done means the available variables and Helm values have consistent documentation and the requested template-update automation is defined.

Written by the indexing model from the issue text.