How to support system property substitution in file config #5926
Description
Do you think it'd make sense to add sth like ${sys:otel.traces.exporter} for system properties as well?
Originally posted by @mateuszrzeszutek in #5914 (review)
Environment variable substitution in file configuration is modeled after the collector, which doesn't have system properties.
System properties are very popular / common in java. How do we support substitution of system properties while keeping with the spirit of collector environment variable substitution?