I put my JAR libraries in the UnrealEngine\Engine\Build\Android\Java\libs
folder.
You can put assets
and res
in your ProjectName\Build\Android
subfolder. So maybe you could drop a jar in ProjectName\Build\Android\libs
.
Then you would need to add JNI to your C++ code. And I didn’t do it that way because it was adding 20 minutes to my compile times. Adding to the engine code was much faster.