[automerger skipped] Move system property for Window Extensions to...

[automerger skipped] Move system property for Window Extensions to WindowManager am: c1ad7f9d -s ours

am skip reason: Merged-In I837ecf978bb42b7da45dd5afdc7d7de0b4d2914e with SHA-1 0dc85ebd is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21475507



Change-Id: Id420a4c502b5a1387e525e6ba722325b8f894fe9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>