feat(main): take `node_config_defaults` out of beta#2098

wyardley wants to merge 4 commits intoterraform-google-modules:masterterraform-google-modules/terraform-google-kubernetes-engine:masterfrom

wyardley:wyardley/promote_node_config_defaults_gawyardley/terraform-google-kubernetes-engine:wyardley/promote_node_config_defaults_gaCopy head branch name to clipboard