DO NOT MERGE: Auto instrumentation paramaters proposal

[jeremydvoss]

Description

Currently, the only way for custom distros to configure is through setting or defaulting environment variables. While it makes sense for customers to configure distros with env vars. There is no reason distros should need be able to directly configure start up (exporters, samplers...etc). Exposing distro configuration of otel via env var defaults is invasive, confusing, and easy for users to mess up. For instrance, even a blank env var or a left over setting from previous run could interfere with a distro starting up.

This is a draft proposal for what changing this approach could look like. In this approach, distros can output kwargs that our sitecustomize setup can then pass to configurators, and by extension the _initialize_components method which currently only considers env vars.

main repo pr: https://github.com/open-telemetry/opentelemetry-python/pull/3864 contrib pr: https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2439