Merge "Updates the doc for FEATURE_WINDOW_MAGNIFICATION" into tm-dev am: 70a4c768

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17394606



Change-Id: Idbf07464a4b62d2f49fe1f3934043b601d49181a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>