They were very clear at the AMA:
"Anwar: Nope, not happening."
"Anwar: We don’t have any plans to officially support a new language in Android, so we’d encourage folks to continue to use Java:) That said, you should continue to use what works for you."
https://www.reddit.com/r/androiddev/comments/4tm8i6/were_on_...
People have to get over the fact that regardless of what happens in the Oracle vs Sun, the Android team which has a quite a few Sun alumnis, doesn't want to use anything else.
Even the NDK is designed in a way that native C and C++ code is always exposed via Java native. The example code on the NDK start page is pretty clear how they see the NDK.
https://developer.android.com/ndk/index.html
"The Android NDK is a toolset that lets you implement parts of your app using native-code languages such as C and C++. For certain types of apps, this can help you reuse code libraries written in those languages."
And another fun fact is that given the NDK constraints, having Linux as kernel doesn't matter that much, they could change to something else and only OEMs would notice.
Even Microsoft is only improving the Objective-C support on their iOS bridge, in spite of the Swift support requests, at least for the time being.
If you check Brillo, which is basically Android without the Java layer, their plans are to create a C++ Frameworks layer not Swift and not Go.
Anything else it is up to the respective language communities to make it work.
Right now only Kotlin seems to be improving their Android support, but that is because JetBrains needs a killer application for it, which appears to be improving the world of those stuck in Java 6.