Change behavior of the SDK namespace prerequisite tasks based on scenario

[ladonnaq]

A prerequisite task was added to the SDK release milestone to ensure that the SDK namespaces are approved prior to SDK generation. This task requires the user to manually enter the approved SDK namespaces. However, the tasks should only be manual for the Greenfield scenario until we have a better approach.

Greenfield TypeSpec scenarios: Since the SDK namespace review & approval process for management plane is still manual (GitHub issue), there is not an automated approach to obtaining the approved SDK namespaces. Near term, the user will need to manually enter the namespaces.

Brownfield TypeSpec scenarios: We already know the existing SDK namespaces names. A pre-populated drop-down box with the SDK namespaces should be available for the user to select.

Brownfield OpenAPI scenarios: We already know the existing SDK namespaces names. A pre-populated drop-down box with the SDK namespaces should be available for the user to select.

Rules
Work item: Epic
Data field names: DataExistingSDKs and MgmtExistingSDKs
Picklist values: "Not Applicable (N/A)", "no", "yes"
If DataExistingSDKs = no, then Greenfield scenario.
If MgmtExistingSDKs = no, then Greenfield scenario.

Open Questions

• Ask Jeffrey if sub-services will be the standard approach used for large management services/RPs, like Compute or Networking. If so, we need to ensure that the release planner knows about relationship between services and sub-services. Will there be service tree entities for these sub-services? We do see this for data plane services like Health Insights.
• If a new sub-service is used for a product with existing SDKs, then the user needs to have the new SDK namespaces reviewed and approved by the arch board. How does an existing service find out that this task is required? The release plan would not notify them because the current workflows would see these scenarios as Brownfield.

Screenshot of the UI with comments