The eZ Publish setup process will "pull" the image alias / variations from legacy, and add them to the config in ezpublish.yml

However, there is also a large list of default alias in eZPublishCoreBundle 's default_settings.yml.
These alias cannot be removed through config, only overriden.

The default list should be as simple as possible (for ex. reference, small, medium, large), other required variations should be moved to their own bundle such as DemoBundle.

Reference:
https://github.com/ezsystems/ezpublish-kernel/blob/9edc1775/eZ/Bundle/EzPublishCoreBundle/Resources/config/default_settings.yml#L114

Steps to reproduce:

1. Remove all variations from ezpublish.yml
2. In admin interface, verify the alias list in injected settings for image.ini