Include `x_forwarded` in workers example configs (#14667)

changelog.d/14667.doc

...b/workers-bash-scripts/create-multiple-generic-workers.md

...ib/workers-bash-scripts/create-multiple-stream-writers.md

docs/systemd-with-workers/workers/event_persister.yaml

docs/systemd-with-workers/workers/generic_worker.yaml

docs/systemd-with-workers/workers/media_worker.yaml