Actually it's not explicitly documented anywhere, so it's an action request to the dev team!
2.4.x versions are binary backward compatible, so if your app asks for 2.4.3 but device has 2.4.5 - the 2.4.5 is loaded.
This sample references the `CvCameraViewListener2` interface that was introduced in 2.4.3, so it requests this version at init.