Code review comment for lp:~fgiff/linaro-android-build-tools/884931

Fair point, .config is ambiguous, but defconfig is potentially misleading too: I want to be clear that this is the kernel config we really used, so if a build makes defconfig and then uses scripts/config to change some options, this artifact is the .config we built and not necessarily the same as the defconfig.

I'll fix this to call it kernel_config unless there are better suggestions.