Replace the libgstreamer plugins suggestions
Replace the libgstreamer plugins suggestions

- The `libgstreamer-plugins*` packages don't include all the dependencies like the
  `gstreamer1.0-plugins-*` do.
- `gstreamer1.0-plugins-ugly` is required on Ubuntu 18.04 (at least) to run the
  `videoplayer.py` example.
kivy/kivy-sdk-packager,kivy/kivy-sdk-packager