Schedule block with hero template height does not reset after removing content item.

Steps:
1. Create a new LP.
2. Add a Schedule block with the hero template.
3. Verify the preview. [screenshot 1]
4. Add a e.g. blog post.
5. Remove the content item.
6. Verify the preview. [screenshot 2]
Actual: Block's height remains as it was with the blog post loaded.
Expected: Block's height resets to default for empty hero.

Remarks: Does not affect List template.