I still see a lot of Java in the AOSP projects. With a proper JIT (not Google's), the memory to performance ratio can be dynamically tuned for each code method. The other big feature that isn't talked about much is that the JIT not only converts generic code to a specific instruction set, but it also generates instructions that work around hardware bugs in a specific version of the chipset. It's exactly what's needed when 5 years worth of phones are running a dozen chipsets that are each upgraded every few months.
The downside of syncing up to OpenJDK is that it may be difficult to prevent developers from draining the battery. Poorly performing "Reflection" and anonymous adapter classes are the secret sauce behind many popular frameworks. Lambdas are the new lightweight solution to anonymous classes but the implementations churn through a lot of temporary memory.