Changes to Get account balance

removed the optional property purchased_next_expiry from the response with the 200 status

added the optional property purchased_expires_at to the response with the 200 status

added the optional property purchased_next_expiry to the response with the 200 status

added the required property included_microdollars to the response with the 200 status

added the required property purchased_microdollars to the response with the 200 status

the endpoint scheme security bearerAuth was removed from the API

api operation id billing-get-balance removed and replaced with billing_get_balance