This documentation currently mapps `Bytes Received` to `server.bytes` and `source.bytes` as well as `Bytes Sent` to `client.bytes` and `destination.bytes`. 

This mapping is incorrect as per the [Palot Alto Docs](https://docs.paloaltonetworks.com/pan-os/10-2/pan-os-admin/monitoring/use-syslog-for-monitoring/syslog-field-descriptions/traffic-log-fields), `bytes_sent` is defined as `Number of bytes in the client-to-server direction of the session.` and matches the ECS definitions for `client.bytes` and `source.bytes` being bytes from `client/source => server/destination`. 

Likewise, `bytes_received` is defined as `Number of bytes in the server-to-client direction of the session.` and matches the `destination.bytes` and `server.bytes` definitions in ECS being the bytes sent from `server/destination => client/source`.

Furthermore, the [panw filebeat module mapping](https://github.com/elastic/beats/blob/v8.4.0/x-pack/filebeat/module/panw/panos/config/input.yml#L95) and [integration pipeline](https://github.com/elastic/integrations/blob/main/packages/panw/data_stream/panos/elasticsearch/ingest_pipeline/traffic.yml#L212) both follow the above conventions. 

This proposed change will map `Bytes Received` to `destination.bytes` and `Bytes Sent` to `client.bytes`.

Swapping the values of `source.bytes` and `destination.bytes` in order to align the documentation with the changes implemented in #18525