I have already checked this post: How to download dependency sources for Gradle project in IDEA?
But it didn\'t work for me. Maybe it is because they are referring t
Currently Android Studio imports libraries with sources. As for java docs press F1.
Old answer:
As we are talking about early preview, simplest fix wins.
For now is just manually add them to the project in Project Structure dialog. Things are even worse as now Android Studio will strip module files (iml) from all dependencies which are not related to native Android Gradle configurations and tasks e.g. module has robolectric dependency and extra task and config localTest is added in build.gradle. After you open Android Studio it will remove dependency, you need to add it again.
For time being I am keeping iml files and .idea folder in my git. After launch
git checkout myproject/myproject.iml