@kerim, the billing permission and the others nessesary permissions are in the google play services extension, do you have it installed in your project?
is your game free to play? or paid to play? if it is free you don't need the licensing extension nor the "licensing code" in the global settings
but if is a paid app then you can keep using the licensing extension. but keep in mind that is not obligatory to use it.
the most important part :
also make sure the "billing" is in capital: com.android.vending.BILLING
not com.android.vending.billing