declarative config: Check that distros and spring starter will be successful eventually

[zeitlinger]

• starter has been explored sufficiently: Spring starter declarative config #14062
• distro is not explored yet: Support declarative configuration for Java distros #14080

[zeitlinger]

I've created a PoC for distros that make me sufficiently confident that we can work it out: grafana/grafana-opentelemetry-java#1062

@jaydeluca can you take a look?