Merge "Only check letterbox position in book mode" into tm-qpr-dev am: edc5058b am: ef53043c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22251403



Change-Id: Ib3205cb6b238994f07cfe687bb9b71c1f4c25e75
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>