Native libraries (.so files) are not added to an android project

As soon as the native libs are in /libs/armeabi/ all you have to do is to configure the android plugin properly. Something like this:

<plugin>
    <groupId>com.jayway.maven.plugins.android.generation2</groupId>
    <artifactId>android-maven-plugin</artifactId>
    <configuration>
         <nativeLibrariesDirectory>${project.basedir}/libs</nativeLibrariesDirectory>
         ...
    </configuration>
    <extensions>true</extensions>
</plugin>