Yeah, Android Java has turned into Google's own version of J++.
Worse is that Kotlin fanboys don't get it, that without access to modern Java their Java FFI is worthless, as all Java 8+ libraries on Maven Central will slowly become useless on Android no matter what.
Additionally the language cannot expose JVM capabilities, unless they had even another backend.
So it will be stuff like value types, JNI replacement, proper generics, customized JIT and SIMD on the JVM, and plain old Java 8 on ART.