[Enhancement] SCP update to accommodate aws-portal service prefix deprecation

[vic614]

Required Basic Info
To properly assess the enhancement request, we require information on the version of the Accelerator you based this request upon:

• Accelerator Version: v1.5.5

Is your feature request related to a problem? Please describe.

AWS has announced the deprecation of service prefix aws-portal (July 6, 2023,). https://aws.amazon.com/blogs/aws-cloud-financial-management/changes-to-aws-billing-cost-management-and-account-consoles-permissions/

aws-portal is currently being used in multiple SCPs.

1. ASEA-Guardrails-Sandbox.json
2. ASEA-Guardrails-Sensitive.json
3. ASEA-Guardrails-Unclass.json

Describe the solution you'd like

Update the SCPs affected.

Describe alternatives you've considered

N/A

Additional context

N/A