I got it! yes at last , i have to study gradles and stuff.
Actually I have 2 android projects inside the Project, one is a library and the other one is the main app.
I found out that when i imported those projects Android Studio (I exported the lib to gradle build from eclipse) doesn’t care if that is a lib project or a main project. (Correct me if im wrong ).
so the only thing to make it work is to remove the intent-filter of that lib-android-project.
EDIT:
@all
solved it ! thanks to everyone, I never knew there was another AndroidManifest.xml , i thought eclipse removed it. and i thought Exporting it to gradle will remove it because it is checked as a library.
thanks for all your help.