"what appears, at a glance, to be clear abuse of market power."
Where is this abuse of market power? If Alibaba wants to release a OS that is an android variant, and if manufacturers want to release phones running that OS, they are still free to do so. But if that OS won't run all android apps, and if apps produced for that OS won't run on Android, then don't expect to have google play store on it, and don't expect support from Google.
In what is this abuse of market power?