Add region tag for Quickstart dependencies (#3632)
Add region tag for Quickstart dependencies (#3632)

This region tag will be used in the new [IAM quickstart](https://cloud.devsite.corp.google.com/iam/docs/quickstart-client-libraries?nocache=717387#client-libraries-install-java)
GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples,GoogleCloudPlatform/java-docs-samples