Hiding split shade media container when not needed

Media container that is used only on the lockscreen in split shade mode is initially visible when user didn't interact with media.
It doesn't contain media player itself, but has padding that interferes with other layout elements. It's properly hidden only after user sees media widget.
This change makes sure that when media should not be visible, every container is marked as GONE.

Fixes: 191010901
Test: restart device and see if empty container is present. HSV after fix: https://hsv.googleplex.com/5408886683074560?node=34
Change-Id: Ib184ba747531da5d288df6381189c5237f1aef6c