[automerge] Keep showing wallpaper when starting an app immediatly after unlock. 2p: f0a9429cc2 am: ef17fbb23d

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16978905

Change-Id: I606b3082d151d58a6fd9df5a1dda3955a37ce0f0