Google specifically disable that kind of functionality in the browser on Android devices.
Either upload the video in to Xibo CMS and use the Video media type to show it, or use the Local Video module which does the same job, but allows you to enter a local path on the device to your movie.mp4 file.
If it must be an HTML5 video item, then you’ll need to attach script to the video html event handlers to detect the end of the video and start it over again.