If you use the example currently defined, exceptions are thrown.  The example doesn't use defined enums values for `billing_provider`, `uom`, `sla`, `usage`.

Example of a working payload:

{
  "account_number": "string",
  "org_id": "string",
  "id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "billing_provider": "red hat",
  "billing_account_id": "string",
  "snapshot_date": "2022-03-10T12:15:50-04:00",
  "product_id": "string",
  "sla": "Premium",
  "usage": "Production",
  "uom": "Cores",
  "value": 0,
  "billing_factor": 0,
  "vendor_product_code": "string"
} 

Reproducer Steps:

1. Start swatch-producer-aws 

   1. DEV_MODE=true ./gradlew :swatch-producer-aws:quarkusDev 

1. Navigate to http://localhost:8000/q/dev-ui/io.quarkus.quarkus-smallrye-openapi/swagger-ui 
2. Under POST /api/swatch-producer-aws/internal/aws/billable_usage, click the Try it out button
3. Hit execute without modifying the example payload