You can have a look at this EventSource polyfill library: https://github.com/Yaffle/EventSource
It's only supported on the Android browser (lower than 4.3 at least) if you add 4k of padding after each message. Perhaps you can also try implementing long polling? It might be a better solution instead of eventsource with 4k padding.
You can read more on this topic here: https://github.com/Yaffle/EventSource/issues/14