As of now, there isn't a direct open-source (FLOSS - Free/Libre and Open Source Software) alternative to LosslessCut available on Android.
Lossless video editing is a feature that's generally found in more advanced video editing tools, which can be challenging to find on mobile platforms, especially within the open-source domain. Open-source apps on Android for video editing are relatively few, and those that exist typically don't have the extensive feature set found in desktop software.
That said, the landscape of available apps is constantly evolving. It might be worthwhile to check on platforms like F-Droid, which is a repository for open-source Android apps. You might find a new app that suits your needs.
Alternatively, if you have access to a remote server, you could potentially use FFmpeg commands to perform lossless cuts on your video. FFmpeg is a powerful open-source tool that can handle a wide variety of video editing tasks. However, this would require a good understanding of how to use FFmpeg and would likely be a more complex solution than using a dedicated app.