Generate configuration event at startup

[breedx-splk]

Relates to #168.

As part of #276, the configuration was decoupled from the initialization events. This TODO says that we should figure out how to pass the config as a map: https://github.com/open-telemetry/opentelemetry-android/pull/276/files#diff-6f33477d17cf7e6844b9afbc97741d317291d28b233fb28f810359611325274fR376

It's really helpful to have an event at startup that provides the o11y practitioner with details about the RUM/agent configuration.

[LikeTheSalad]

Apart from avoiding a circular dependency, do you think there are other reasons where transforming the config object into a map could be beneficial? I'm asking because I think we could work around the circular dependency issue, so we might be able to avoid doing this work altogether.