Airflow variables configuration

[bcarranza]

What

• Apache Airflow configuration options can be attached to your Amazon Managed Workflows for Apache Airflow environment as environment variables
• Our airflow module didn't has this input variable
• Now is available to use

Evidence of proof

 # aws_mwaa_environment.this will be updated in-place
  ~ resource "aws_mwaa_environment" "this" {
      ~ airflow_configuration_options   = (sensitive value)
        id                              = "dp-dev-airflow"
        name                            = "dp-dev-airflow"
        tags                            = {
            "ops_env"              = "dp-dev"
            "ops_managed_by"       = "terraform"
            "ops_owners"           = "devops"
            "ops_source_repo"      = "gruntwork-infrastructure-live"
            "ops_source_repo_path" = "dp-dev/us-west-2/dp-dev/dataplatform/0300-airflow"
        }
        # (19 unchanged attributes hidden)

        # (2 unchanged blocks hidden)
    }

• Code where I am using this branch? https://github.com/exact-payments/gruntwork-infrastructure-live/pull/1703/files#diff-e4143fcd8122afe514798c50b3da9921016ca80f396b4e1e4743c4c667ffce12R140-R146