DO NOT MERGE: test building libvlc.so with outside script

To allow standalone libvlcjni gradle build.

buildsystem/compile-libvlc.sh

@@ -265,7 +265,7 @@ avlc_pkgconfig()
 
 avlc_build()
 {
-$LIBVLCJNI_SRC_DIR/buildsystem/build-libvlc.sh -a $ANDROID_ABI $LIBVLC_RELEASE $LIBVLC_PACKAGE_CONTRIBS $LIBVLC_PREBUILT_CONTRIBS
+$VLC_SRC_DIR/extras/package/android/build-libvlc.sh --libvlc-prefix $LIBVLCJNI_SRC_DIR/libvlc/jni -a $ANDROID_ABI $LIBVLC_RELEASE $LIBVLC_PACKAGE_CONTRIBS $LIBVLC_PREBUILT_CONTRIBS
 
 if [ "$AVLC_BUILD_JNI" = "1" ]; then
     $LIBVLCJNI_SRC_DIR/buildsystem/build-libvlcjni.sh -a $ANDROID_ABI $LIBVLC_RELEASE