|Forking Android into another OS is one thing. Getting enough developers to support it and make apps for it is another. You can see what having one hardware vendor selling phones for iOS has done to Apple's market share, and that's with access to the Chinese market.|
I don't anticipate Huawei having much success with a 3rd OS for smartphones, especially if they can't sell them in the U.S. They will doom themselves to be niche players that sell only to China and other countries that don't care about security. Good luck with that. Heck, perhaps that is Huawei's plan all along, since producing their own OS will allow the government to monitor their citizens even more than they already do. They can put all kinds of spyware into the code.
The Huawei issue is a just symptom of the larger trade war, and it's one Trump will have a hard time winning. Even if he places tariffs on all remaining imports from China, it will only hurt the U.S. economy. If Trump manages to win another term, Xi and China will simply wait it out, since the likelihood of another Republican being elected president after his time in office is over is very low. Certainly no Democrat will continue the trade war.
The Chinese government doesn't care how much the trade ward affects their people because it doesn't care about them. Unlike the U.S., they don't have to.