Enabling For Distribution doesn't set config to Shipping in DefaultGame.ini

After I ran the above steps and then packaged for Windows and iOS (using File > Package in the editor), my resulting executable was Shipping.

So far this issue is cosmetic / confusing to the user only, according to my testing. However a user on Answerhub is having trouble with with their Shipping builds and believes this could be the cause. We'll need more info about how they compile or make their package to determine whether this is what is blocking them.

I tested on both Windows 7 and MacOS High Sierra.

1. Create a project and run the editor
2. Open the DefaultGame.ini
3. Go to Project Settings > Packaging
4. Set Build Configuration to something else, then set it back to Development
(note that the ini updates)
5. Enable For Distribution

RESULT: The UI automatically sets the build configuration to Shipping, but the ini only sets ForDistribution=True, without setting the BuildConfiguration to Shipping

EXPECTED: The ini to set BuildConfiguration to Shipping