AOSP at the very least, but the average consumer doesn’t really care much about Google Play Services or their Mainland China substitutes (obv cos great firewall).
Or for Mainland Chinese devices, their carrier or manufacturer equivalents of GMS aka China Unicom “WO” services and Huawei/Xiaomi/Meizu services respectively (or whatever they are natively called there).
I remembered CBC News also had an instant app exactly like you described at one point.