Android res/layout Folder not included in the APK file (but included in the ANE)

I'm having a problem with resources on an Adobe ANE Android extension:  android.content.res.Resources@NotFoundException:  id.viewView

I have a xml layout file, which is included in the ANE file (checking by unzipping the ANE file and looking into META-INF/ANE/Android-ARM)

In the APK file (generated with Flash Builder 4.6), the layout folder (inside res) at the top level is missing, but its included deep in the assets folder:

    - META-INF   

    - res

        drawable

        drawable-hdpi

        drawable-ldpi

        drawable-mdpi

        raw

    - assets

        META-INF

            AIR

                extensions

                    org.dornad.ane.MyTestExtension

                        META-INF

                            ANE

                                Android-ARM

                                        drawable-hdpi

                                        drawable-mdpi

                                        drawable-xhdpi

                                        layout

                                        values

Any ideas?