Merge AppWindowToken into ActivityRecord

This change kept AppWindowTokenTests as it's originally based on top of
WindowTestBase, and merging that into ActivityRecordTests needs to
change the base class to ActivityTestBase, which requires additional
work and may change test behaviors. Therefore delay that to
follow-up CL.

Bug: 80414790
Test: Existing tests pass.
Change-Id: I6d73975ee77be9817c41b297f067de2d92a68499
diff --git a/services/core/java/com/android/server/wm/DisplayRotation.java b/services/core/java/com/android/server/wm/DisplayRotation.java
index 414e496..67f1d1b 100644
--- a/services/core/java/com/android/server/wm/DisplayRotation.java
+++ b/services/core/java/com/android/server/wm/DisplayRotation.java
@@ -520,7 +520,7 @@
 
         // If the bounds of activity window is different from its parent, then reject to be seamless
         // because the window position may change after rotation that will look like a sudden jump.
-        if (w.mAppToken != null && !w.mAppToken.matchParentBounds()) {
+        if (w.mActivityRecord != null && !w.mActivityRecord.matchParentBounds()) {
             return false;
         }