I did it like this:
cocos gen-libs -c -p android --app-abi armeabi-v7a
-c should clean first, right?
I did make changes too.
Log:
01-24 10:47:35.411 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background1.ogg done loading. Result: success
01-24 10:47:35.493 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background2.ogg done loading. Result: success
01-24 10:47:35.509 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background8.ogg done loading. Result: success
01-24 10:47:35.526 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background5.ogg done loading. Result: success
01-24 10:47:35.526 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background6.ogg done loading. Result: success
01-24 10:47:35.526 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background4.ogg done loading. Result: success
01-24 10:47:35.526 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background9.ogg done loading. Result: success
01-24 10:47:35.542 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background7.ogg done loading. Result: success
01-24 10:47:35.542 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background3.ogg done loading. Result: success
01-24 10:47:35.542 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: background10.ogg done loading. Result: success
01-24 10:47:35.542 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: All done!
01-24 10:47:35.542 5314-6092/org.cocos2dx.ProjectName D/cocos2d-x debug info: loading took: 2184 ms