Merge "Adjust smallestScreenWidthDp for letterbox" into tm-qpr-dev am: ac2768ae43 am: b8a0696c35

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19416406

Change-Id: I2bf93ec0580aa58f03c16c531141b4d1b6698cbe
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>