Huawei seems to be planning to release another OS with Android and webapp capabilities. Talks currently with aptoide (not US based). I suspect this will open the door for non-google android (Amazon is already doing that, but as more join, more devs will).
So I do think it might create a 'third option' on mobile, but rather than an OS, simply Android without google, and perhaps PWA (which lets face it, would be a wise dev investment in an uncertain market)
I also don't think this is just about a trade war. To me, that's sort of a pretext. China doesn't like having US tech, US doesn't like having Chinese tech, Russia doesn't like having US tech, etc. China right now is all amount making moves to reduce US components and has long banned Google for similar reasons. Russia made a deal awhile back with sailfish for similar reasons.
Really, the US is late to the game, of this mutually, and the realistically paranoid tech war about national infrastructure and informational security.
There are programs embedded in CPUs for example, that could be used as foreign govt backdoors to leak information. Similarly, foreign hardware could be designed with kill switches to use to shut down essential infrastructure in a war. China and Russia have both focused development and planning along lines of infrastructure, sabotage attacks, in case of a war with America. And nobody wants their secrets leaked.
Foreign tech, belonging to other superpowers is a security liability. Obviously the US lacks the resources to homebake all it's hardware, and China lacks any viable operating systems for international business. Russia has even less options. So it's an uneasy situation, and IMO this is a manifestation of that, as much as any trade war.
Should tariffs and so on calm down, I fully expect bans to continue on certain key infrastructure both in the US and in China. I also expect companies like Microsoft will have to give China meaningful assurances and places like Taiwan etc, will likely pick up a lot of the hardware slack.