Remove obsolete shadow logic from StackScrollAlgorithm updateChildZValue

Removed childrenOnTop. When you send a bunch of delayed HUNs, the newest HUN pushes the previously pinned HUN downwards, so there's always a max of one pinned HUN. Thus childrenOnTop is no longer needed.

Bug: 259278944
Test: StackScrollAlgorithmTest
Change-Id: I47446170c3199769e78521f80ed3982e2e8554a4
2 files changed