too many languages in apk

I made a free version of my app which uses AdMob. When building the app and uploading it, the Google Developer Console says my app supports 72 languages. It should only be 2.

Running "aapt d badging" on my app shows a lot of "application-label-XX: lines and under "locales:" a lot of language codes.

The version without admob has there only '--_--'.

Where does this come from? Is this from AdMob? How can I change this? Has anyone a clue?