Merge "[1/n] Move Letterbox education dialog classes" into tm-qpr-dev am: 812e3291

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/21911723



Change-Id: Ie82fa96ac48632c985313c64fc2fc52821040211
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>