I am seeing hints of ANT / JAVA support for Android in 3.8.1
documentation. Essentially there is a whole list of properties that
have unexplained use cases under Properties for Targets. I see
ANDROID_JAVA_SOURCE_DIR, for example. What are these for? Will CMake
actually do the "ant release" command for you? I've been using custom
targets to do the java build & packaging steps for Android.