In the 4.x SDK, if the app launches from the background less than five minutes from the previous launch, it counts as a resume, but past five minutes (by default) it counts as a new launch.
Was it the same way in 2.x? Was there a time distinction between resume and launch, or some analogue of the lifecycleTimeout field?
Also: where can I find documentation about 2.x? I have some legacy code that had it (which is no longer in production) and am frequently asked about how things have changed. Questions like that are hard to answer if I don't know how it should have behaved when the code was using the 2.x version of the SDK.
Here is the link to Android 2.x Appmeasurement:
Note that Appmeasurement for Android was 1.x and iOS was 2.x; Android went from 1.x to 3.x. This is why the doc says it's for version 1.x, but it's the one you're looking for.
The migration documentation does not cover how resume or launch were handled in 2.x.