They dont acturally need to change the liscense at all, despite what most people think (and would logically make sense) AOSP is acturally downstream from Android. So basically as we're seeing right now if Android doesn't want to release the source code for something they just need to not push it to AOSP. It has been over two months already and Android 16 QPR1 still hadn't been upstreamed to AOSP nor are they legally required to (they are legally required to publish kernel sources which they have failed to do).