GovCloud support

[atheiman]

Tried running this in us-gov-west-1, got these errors. Pretty easy fixes

│ Error: creating CodeBuild Project (aws-sce-tf-community-ugw-runner): operation error CodeBuild: CreateProject, https response error StatusCode: 400, RequestID: 9b4fd14c-c7c6-40e3-8b82-bf0a6ee1b6c7, InvalidInputException: The environment type ARM_CONTAINER and compute type BUILD_GENERAL1_LARGE combination is not supported in us-gov-west-1
│
│   with module.svc_ctlg_engine.aws_codebuild_project.sce_runner,
│   on .terraform/modules/svc_ctlg_engine/codebuild.tf line 4, in resource "aws_codebuild_project" "sce_runner":
│    4: resource "aws_codebuild_project" "sce_runner" {

aws_codebuild_project.environment arguments compute_type and type should be customizable via variable

│ Error: putting IAM Role (TerraformExecutionRole-codebuild-runner) Policy (aws-sce-tf-community-ugw-codebuild-runner): operation error IAM: PutRolePolicy, https response error StatusCode: 400, RequestID: 9dba2594-6911-42c3-a005-648f4824265b, MalformedPolicyDocument: Partition "aws" is not valid for resource "arn:aws:iam::*:role/*".
│
│   with module.svc_ctlg_engine.aws_iam_role_policy.sce_codebuild_runner,
│   on .terraform/modules/svc_ctlg_engine/iam.tf line 47, in resource "aws_iam_role_policy" "sce_codebuild_runner":
│   47: resource "aws_iam_role_policy" "sce_codebuild_runner" {

Partition should be loaded from data.aws_partition.