Update AWS Menu Item to Create Database

What does this MR do?

Update the AWS menu item for step 1 under Create Database to read Databases instead of Instances to align with current AWS UI.

Related issues

See #197154 (closed)

Author's checklist

• Follow the Documentation Guidelines and Style Guide.
• If applicable, update the permissions table.
• Link docs to and from the higher-level index page, plus other related docs where helpful.
• Apply the documentation label.