Sync Outdated Terraform Buildkite Pipelines for bazel Org (#2470)

Sync terraform files for : **bazel** org

1. Updated Buildkite provider version
2. Imported existing pipelines
3. Better formatting
4. Split files for easier diff

Used
[-generate-config-out](https://developer.hashicorp.com/terraform/language/import/generating-configuration)terraform
flag + script to pull and set provider settings (the generate import
doesn't pull them by default)