chore: use default layout for embedded stories

What does this MR do?

This removes the logic that set fullscreen layout for embedded stories. This was meant to remove some padding from embedded docs pages in Pajamas but didn't actually have the expected effected. Instead of removing the padding from docs pages, it removed it from stories, which looked kinda weird and isn't needed. We might want to find a better way to properly size docs pages, but we can get rid of this logic for now.

Before	After