[Bug] Resolve VPC Service Controls state lock during member updates

[aghassemlouei]

Bug Description

Adding a Service Account to perimeter_additional_members via Terraform fails unless the VPC Service Control is manually deleted from the console first.

Environment and Deployment Context

Please provide details about your deployment to help us reproduce the issue.

• Stellar Engine Version/Commit: main
• Deployment Type:
  • US Region Restricted (e.g., Access Policy constraint)
  • FedRAMP Medium
  • FedRAMP High
  • DoD IL4
  • DoD IL5
  • Stand-alone / Custom
• FAST Stage (if applicable):
  • Stage 0 (Bootstrap)
  • Stage 1 (Resource Management)
  • Stage 2 (Network Creation)
  • Stage 3 (Security and Audit)
• Affected Component: blueprints/fedramp-high/access-context-manager/
• Terraform Version: 1.5.7
• GCP Provider Version: 5.10.0

Steps to Reproduce

Steps to reproduce the behavior:

1. Deploy initial VPC SC perimeter.
2. Update Terraform variables to add a Service Account to perimeter_additional_members.
3. Run terraform plan / apply.
4. Observe state lock failure.

Expected Behavior

The VPC SC perimeter should update gracefully via the API without requiring manual deletion.

Actual Behavior

Terraform fails to apply the update, requiring the user to navigate to the GCP console and delete the perimeter manually.

Relevant Logs and Errors

N/A

Additional Context

This breaks the automation workflow for network environments. This was explicitly requested in the legacy Feature Braindump from 2023.

[Calvin-Cheng1]

@aghassemlouei Can you provide some more context to this issue? perimeter_additional_members is not a valid parameter to pass into the module or the terraform resource itself. Are you referring to adding members within the access levels?