This is an example of how to build NDK projects with Gradle using a simple bash script to wrap calls to ndk-build.
The Android gradle plugin does not yet provide NDK integration, so here we are. See discussion on StackOverflow.
In Android Studio, Import Project. Select "Use auto-import" and "Use default gradle wrapper". The wrapper specifies the gradle distribution to use in ./gradle/gradle-wrapper.properties.
Once the project is imported, simply use jni/ndk-build.sh in place of ndk-build. This script runs ndk-build, and then converts all resulting shared libraries (*.so) to .jars and copies them to the libs folder. Our build.gradle file includes a dynamic dependency on all .jars in libs/, so it should just work.