Add span descriptions for OkHttp child spans

[kahest]

Description

Currently, the parent span http.client has a description and therefore the span summary shows stats grouped by description (e.g. separate for specific endpoints).

OTOH, the child spans (e.g. http.client.connection and below) are all mashed into one (unnamed span) group because they don't have a description set. Therefore you can’t see stats separated by endpoint.

For the span summary module we should add duplicate the description for the child spans. This will likely also be relevant/required for a more span oriented world and Performance v2.

[romtsn]

@kahest I'm gonna move this to sentry-java as the instrumentation itself lives there

[Lisio]

Same story with sentry-php. Setting description for the span solves it and shows that description under "name" column.

[kahest]

Same story with sentry-php. Setting description for the span solves it and shows that description under "name" column.

Can you clarify which spans are affected?

cc @cleptric

[Lisio]

Direct children of transaction. If I don't call setDescription for them, they'll be shown as (unnamed span). It's not very obvious that description = name.

[kahest]

@Lisio so you're creating custom spans - that's a different topic, but we'll take a note that the docs on custom instrumentation could be improved by explaining the reasons for setting a span description.