[automerge] Set the offset of the dim layer of DisplayArea. 2p: b1bd44227c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16919251

Bug: 217637411
Change-Id: I1a6af479a5820ec77d927394709eed288b328a6a
Merged-In: I8fd3494a3cd7ad6183ce6aa442e49f85b441c73f

services/core/java/com/android/server/wm/DisplayArea.java

@@ -644,7 +644,9 @@ public class DisplayArea<T extends WindowContainer> extends WindowContainer<T> {
         void prepareSurfaces() {
             mDimmer.resetDimStates();
             super.prepareSurfaces();
+            // Bounds need to be relative, as the dim layer is a child.
             getBounds(mTmpDimBoundsRect);
+            mTmpDimBoundsRect.offsetTo(0 /* newLeft */, 0 /* newTop */);
 
             // If SystemUI is dragging for recents, we want to reset the dim state so any dim layer
             // on the display level fades out.