To produce an Android app the Android build system converts Java byte code to Dalvik/ART byte code, and currently that conversion process only support convertin

To produce an Android app the Android build system converts Java byte code to Dalvik/ART byte code, and currently that conversion process only support converting Java 7 and lower. If you wrote the new code needed to support Java 8 byte code to Dalvik/ART byte code then you can get Java 8 support, but Google has no plans to do that at the moment as it would take quite a bit of effort. These JVM based languages are able to support the latest and greatest features however because they end up compiling down to Java 7 byte code, which can in turn be converted to Dalvik/ART byte code.