1 Copy Source Code

2 Build the system

3 make idgen

mmm development/tools/idegen/
Which will build idegen.jar into out
and will come out android.iml and so on

4 Open AS and select the android.iml

Warnning: idegen.jar is very important otherwise will not import into AS

If not want to build the system you can copy following content into your project:

android.iml
android.ipr
android.iws
out/host/