I can assure you that we audit the dependencies used in our SDK and update them as needed if any important security fixes are released. If this means migrating to a new repository for a dependency, that will be done at the time of the update. 
We are using exoplayer in our app. It references latest 2.15.0 version, but 2.15.0 removes a ui class your mobilertc references…
This is a dependency conflict, so the only immediate solution available for you would be to use the same version as the SDK. We can certainly investigate updating to 2.15.0, but may not be able to do so for some time since it appears to introduce breaking changes. I’ll be sure to keep you updated as soon as we have finished investigating this.
Thanks!