Move ImageWallpaper.java into package 'com.android.systemui.wallpapers' am: 369f1b973e am: 6417667198

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19695564

Change-Id: Ie217fe1ac22f17007903284cd6a476748cd87244
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>