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

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

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



Change-Id: I70bc474b13d2c2c49865b9b0683a4ddb5ac707ff
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>