Attachments are lost when publishing a collaborative draft proposal

1. When a collaborative draft is converted or published as proposal the attachment image is lost. 2. I expect the attachment to be inherited. 3 I found this bug here: -Collaborative draft: https://meta.decidim.org/processes/decidim-gov/f/961/collaborative_drafts/27 - Published proposal without the image: https://meta.decidim.org/processes/decidim-gov/f/961/proposals/13638