Crop windowing layer to that of display size in screen rotation animation

* Wallpaper is larger than display bounds,
so rotating launcher or other apps that are not
opaque will show the wallpaper in background

Bug: 222632469
Change-Id: I1b23e1da0d8acffdbe7245030095a029e314af0f

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

@@ -600,7 +600,7 @@ class ScreenRotationAnimation {
         }
 
         private SurfaceAnimator startDisplayRotation() {
-            return startAnimation(initializeBuilder()
+            SurfaceAnimator animator = startAnimation(initializeBuilder()
                             .setAnimationLeashParent(mDisplayContent.getSurfaceControl())
                             .setSurfaceControl(mDisplayContent.getWindowingLayer())
                             .setParentSurfaceControl(mDisplayContent.getSurfaceControl())
@@ -609,6 +609,13 @@ class ScreenRotationAnimation {
                             .build(),
                     createWindowAnimationSpec(mRotateEnterAnimation),
                     this::onAnimationEnd);
+
+            // Crop the animation leash to avoid extended wallpaper from showing over
+            // mBackColorSurface
+            Rect displayBounds = mDisplayContent.getBounds();
+            mDisplayContent.getPendingTransaction()
+                    .setWindowCrop(animator.mLeash, displayBounds.width(), displayBounds.height());
+            return animator;
         }
 
         private SurfaceAnimator startScreenshotAlphaAnimation() {