You can start from the BOT libre SDK and modify it to suit your needs. The SDK is no the entire BOT libre app, the BOT libre app was built using the SDK.
The one issue you will have is that Android has a generated R class that is app package specific. So when you change the manifest package for you own, you will need to change the R import package in all of the files. You can uses a multi file search and replace from an IDE, or text editor for this.
We are about to do a major update to the SDK and app that adds support for the new video avatars, actions, and poses. It doesn't change any of the structure or API, just adds a few things, so should not be difficult to merge.