Merge "Revert "Remove obsolete shadow logic from StackScrollAlgorithm...

Merge "Revert "Remove obsolete shadow logic from StackScrollAlgorithm updateChildZValue"" into tm-qpr-dev am: 83e97973 am: ee02d76c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21407165



Change-Id: I7d11137f7ac5d8ff550090052f6311244735a271
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>