Add data-pipeline to staging

[stephen-soltesz]

This change adds the data-pipeline deployment to mlab-staging project. This change follows #29 and is a dependency for all changes to the data pipeline services that will run in this new cluster.

• Rename data-pipeline configurations (us-central1 migration) etl#1124
• Rename data-pipeline configurations (us-central1 migration) etl-gardener#431
• Use build variable for cluster name downloader#45
• Use CLUSTER_NAME variable in cloudbuild.yaml autoloader#24
• Rename data-pipeline configurations (us-central1 migration) stats-pipeline#114
• Prepare for data-pipeline us-central1 migration prometheus-support#1002

Part of:

• Migrate data-processing clusters to us-central1 etl#1092

I have manually imported the stats-pipeline service account in to the mlab-staging terraform state.

$ terraform import module.data-pipeline.google_service_account.stats_pipeline  projects/mlab-staging/serviceAccounts/[email protected]
module.data-pipeline.google_service_account.stats_pipeline: Importing from ID "projects/mlab-staging/serviceAccounts/[email protected]"...
module.data-pipeline.google_service_account.stats_pipeline: Import prepared!
  Prepared google_service_account for import
module.data-pipeline.google_service_account.stats_pipeline: Refreshing state... [id=projects/mlab-staging/serviceAccounts/[email protected]]
module.platform-cluster.data.google_compute_default_service_account.default: Reading...
module.platform-cluster.data.google_project.project: Reading...
module.platform-cluster.data.google_compute_default_service_account.default: Read complete after 0s [id=projects/mlab-staging/serviceAccounts/[email protected]]
module.platform-cluster.data.google_project.project: Read complete after 1s [id=projects/mlab-staging]

Import successful!

The resources that were imported are shown above. These resources are now in
your Terraform state and will henceforth be managed by Terraform.

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This change is 

[nkinkade]

Reviewed 2 of 2 files at r1, all commit messages.
Reviewable status: complete! 1 of 1 approvals obtained