[Microsoft.Billing]: Updating swagger with rename changes required.

[SamhitaK6]

Latest improvements:

MSFT employees can try out our new experience at OpenAPI Hub - one location for using our validation tools and finding your workflow.

Contribution checklist:

• I have reviewed the documentation for the workflow.
• Validation tools were run on swagger spec(s) and have all been fixed in this PR.
• The OpenAPI Hub was used for checking validation status and next steps.

[openapi-portal-comment]

If you're a MSFT employee, click this link
to view this PR's validation status on our new OpenAPI Hub spec management tool.

[AutorestCI]

Automation for azure-sdk-for-python

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-python#3853

[AutorestCI]

Automation for azure-sdk-for-js

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-js#555

[AutorestCI]

Automation for azure-sdk-for-node

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-node#4163

[AutorestCI]

Automation for azure-sdk-for-ruby

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-ruby#1943

[AutorestCI]

Automation for azure-sdk-for-go

Nothing to generate for azure-sdk-for-go

[AutorestCI]

Automation for azure-sdk-for-java

The initial PR has been merged into your service PR:
Azure/azure-sdk-for-java#2637

[azuresdkci]

Can one of the admins verify this patch?

[KrisBash]

Signing off for ARM