CLI: Updating app icons fails due to android-adaptive-background.png

The cli does as the documentation explains:
```
By default, the generator will exit if the input-files in your templates folder match signatures with those of the default Ignite app-icons - this is done to encourage you to make actual changes to the icons before generating.
```

What's feels strange is that the file `android-adaptive-background.png` is really just a basic grayscale background. I'm ok with that default, I have in fact used sketch to update the icon/logo and exported as suggested, but I had no reason to update that background file. So i am forced to use the `--skip-source-equality-validation` flag which makes me think I must change that background file too.

Is that as expected? should I be modifying that background even though my logo doesn't really require one?

Start with the documented source-equality validation and reproduce the failure involving android-adaptive-background.png. Check how the --skip-source-equality-validation flag is described and whether the expected handling of an unchanged background is documented. Done means the expected behavior and any required icon-file changes are clear to users.

Written by the indexing model from the issue text.