EarlyInitAgentConfig should use declarative configuration

[zeitlinger]

Blocked by #14131

[laurit]

I don't think it can use the declarative configuration. These properties are needed before the otel sdk is initialized.

[zeitlinger]

I don't think it can use the declarative configuration. These properties are needed before the otel sdk is initialized.

we can load the config file before the SDK - like in #14048