code: private void extractAarLib( Artifact aarArtifact ) throws MojoExecutionException
      {
          getUnpackedLibHelper().extractAarLib( aarArtifact );
  
          // Copy the assets to the the combinedAssets folder, but only if an APK build.
          // Ie we only want to package assets that we own.
          // Assets should only live within their owners or the final APK.
          if ( isAPKBuild() )
          {
              copyFolder( getUnpackedLibAssetsFolder( aarArtifact ), combinedAssets );
          }
  
          // Aar lib resources should only be included if we are building an apk.
          // So we need to extract them into a folder that we then add to the resource classpath.
          if ( isAPKBuild() )
          {
              // (If we are including SYSTEM_SCOPE artifacts when considering resources for APK packaging)
              // then adding the AAR resources to the project would have them added twice.
              getLog().debug( "Not adding AAR resources to resource classpath : " + aarArtifact );
          }
      }
docs: Extracts AarLib and if this is an APK build then adds the assets and resources to the build.