Indicators not appearing on timeline for Schedule block.

Steps:
1. Create new LP.
2. Add Schedule block.
3. Add content.
4. Verify timeline indicators.
Actual: Indicator (purple) does not appear.
Expected: Indicator is displayed.
5. Open airtime settings.
6. Move to the future.
7. Add content.
8. Confirm push-out.
9. Verify timeline indicators.
Actual: Indicator (purple) does not appear.
Expected: Indicator is displayed.

Remarks: Does not affect 1.7.
Items in Full list view are correctly added.