Record Accessor in Datadog's dd_service

[edgarrmondragon]

Is your feature request related to a problem? Please describe.

It would be nice to be able to use the Record Accessor to set the service attribute to something like $kubernetes['container_name'].

Describe the solution you'd like

Being able to use $kubernetes['container_name'] for dd_service in the Datadog output.

Describe alternatives you've considered

Using filters to add a service field that Datadog automatically recognizes: https://docs.datadoghq.com/logs/log_configuration/pipelines/?tab=service#service-attribute

Additional context