Liftoff is Imported twice

[brenofurlanpixo]

This occurs only with the new update regarding the use of Unity Package Manager to install the mediation provider

There's also some missing .meta files for the android library:

Checking on your Github repo, it has included an package folder along with the source folder, resulting in the above.
For now, we can't continue to use Liftoff due to this issue.

[Edit] typo

[CheeryLee]

Agreed. As a workaround it could be imported using the old way from unitypackage.
But I'm looking forward to solving this problem.