[flexiglass] Use intrinsicHeight for HUN placeholder and update translation

Fixes two issues: the HUN not being translated correctly while being dragged, and the placeholder not updating its height correctly when the HUN is expanded/collapsed after being dragged and expanded during shade expansion.

Bug: 357661886
Test: manually verified HUN is no longer clipped behind QQS tiles when shade is expanded via dragging on a HUN
Test: manually verified HUN placeholder height is correctly updated to match pinned notif height in shade
Flag: com.android.systemui.scene_container
Change-Id: Ic7e9460f3f87f6315c232709747cdb062f98340e