Crosswalk is non viable until it reduces overhead, adding 20MB to your project into the APK is a sin when we are working with 50MB limits.
Anyway to add something like?:
public static final int PARTIAL_WAKE_LOCK
Allowing screen to black out but CPU keeps game active, upon resume it should resume as normal.
Edit: I found a var in the runtime on C2 cocoon export, autolock, its set to enable, allowing the device to go into sleep mode on a period of inactivity. I have changed this to disabled, and compiling it again to test. Fingers crossed.
Edit2: It works. Ingame, the device will not go to sleep mode.