I think it's more likely that we'll see Go, Dart, JavaScript, or even Swift become a first-class development option on Android.
Swift would be especially nice. How fantastic it would be to be able to use the same language to target the two most popular mobile platforms? Of course Swift is also probably the least likely since Google is still smarting from the Oracle/Java debacle. The last thing they need is another decade-long copyright infringement fight with the richest company in the world...
That would be a little foolhardy on Google's part, don't you think? Considering the ongoing 'API copyright' wrangle that is Oracle v. Google
I do believe that Google will continue to lose as the history of the East Texas juries for IP is almost always gifting the patent/copyright holder. I wish our system had some kind of venue randomizer. Its clear that this district is a moneymaker for IP holders.
So now we have J++ on Android.
Or, conversely, if they'd bought Sun instead of letting Oracle do so, stripped interesting IP (particularly, Java), and sold the rest back off (see, e.g., what they did with Motorola Mobility.)
But given Dart and Go I am not sure if it would have been a good idea in what concerns language evolution.
If you take a look at the public commit on the AOSP jack & jill repo, you can see that google is working on Java 8 integration : https://android-review.googlesource.com/#/c/150214/2/jack-te...
It is very surprising though, I would have expected Google to explore other options due to the hard back compatibility story and with Oracle ready to push this legal battle as far as possible.
As far as Swift on Android ? From a developer point of view, there would probably be far worse choices (one could argue that Kotlin would be a better choice, if only because of Java 6 as a target) but yeah even without considering the legal aspect, I doubt that Google would be ready to use a language managed by its direct competitor.