docs: Clarified that field `metadata` in `google.rpc.ErrorInfo` should be lowerCamelCase
feat: Improved support for multiple `google.rpc.BadRequest.FieldViolation` errors
Added `reason` and `localized_messsage` fields to `google.rpc.BadRequest.FieldViolation`. This allows each violation to have a machine readable identifier and error message that is safe to return to the API consumer.
PiperOrigin-RevId: 707591563