According to Sammobile, the Galaxy S4 of Google Edition has begun to test Android 5.0. Of course, it uses the native Android system, which is much easier to adapt than the general customized Android system.
The Galaxy S4 model of Google Edition is GT-I9505G, which uses Snapdragon 600 1.9GHz processor.
The following is the screenshot of Android 5.0 system of Google Edition Galaxy S4:
