Azure: Deploying from Azure Marketplace is failing

Summary: I've tried creating Couchbase clusters from the Azure marketplace multiple times, and it keeps failing.

Repro:

1. Go through the normal steps of creating a Couchbase cluster from Azure Marketplace. I'm using Couchbase Enterprise (BYOL). I've tried 1 node, 3 node. I've tried with the various VM sizes, including both suggested sizes and otherwise.
2. I am always selecting 0 Sync Gateway nodes (not sure if it matters, but MB-26387 suggests this may have been a problem in the past)
3. Wait for the deployment to finish.

Expected:

Successful deployment, ready to login.

Actual:

Error messages in the Azure Activity log. (See screenshots and attached JSON output)