It is quite surprise to hear that Acer will stop using Android OS but using Aliyun. Aliyun is a new mobile operating system by Alibaba which is the top ecommerce company in China. Why? Now there is not official announcement from Acer over this switch.
Now the only reaction is that Alibaba said that Google threatened to cancel the license with Acer if the company switch to use Aliyun. In fact, Acer planned to launch an event on Thursday in China to announce Acer A800 which runs on Android but now the event is cancelled. Nothing so far from Acer leaving doubt for the change.
Note that Aliyun can use Android apps by cloud apps.