android.os.ServiceManager not found while building

I am getting following error while building android source, where i have added my custom app which uses android.os.ServiceManager. ``` cannot find symbol symbol : class ServiceManager location: package android.os import android.os.ServiceManager; ``` Why am I facing this error, actually this import can be found in many other app in android source. I am building the android source as in http://source.android.com/source/building.html and also followed this post The import android.os.ServiceManager cannot be resolved answers. and for more info, I am building in [android root]/packages/app/ directory Please can anybody help me to solve this ?