Prevent ZBoost of TaskDisplayArea

Before, when an activity needs z boost, the whole TDA is moved above
other windows of ABOVE_TASKS. Now, we don't move TDA anymore.

Fix: 149651594
Test: manual: open app and expand notification before app fully start,
the app no longer moves above notification.
Test: atest WmTests:TaskDisplayAreaTests#testActivityWithZBoost_TaskDisplayAreaDoesNotMovedUp

Change-Id: Ie1eae7a5566fc8988cd3ca9f4a56332743facf52

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

@@ -106,6 +106,12 @@ public class DisplayArea<T extends WindowContainer> extends WindowContainer<T> {
         }
     }
 
+    @Override
+    boolean needsZBoost() {
+        // Z Boost should only happen at or below the ActivityStack level.
+        return false;
+    }
+
     @Override
     boolean fillsParent() {
         return true;

services/tests/wmtests/src/com/android/server/wm/TaskDisplayAreaTests.java

@@ -40,6 +40,9 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
 
 import android.platform.test.annotations.Presubmit;
 
@@ -81,6 +84,25 @@ public class TaskDisplayAreaTests extends WindowTestsBase {
         mPinnedStack.removeImmediately();
     }
 
+    @Test
+    public void testActivityWithZBoost_taskDisplayAreaDoesNotMoveUp() {
+        final ActivityStack stack = createTaskStackOnDisplay(
+                WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD, mDisplayContent);
+        final Task task = createTaskInStack(stack, 0 /* userId */);
+        final ActivityRecord activity = WindowTestUtils.createTestActivityRecord(mDisplayContent);
+        task.addChild(activity, 0 /* addPos */);
+        final TaskDisplayArea taskDisplayArea = activity.getDisplayArea();
+        activity.mNeedsAnimationBoundsLayer = true;
+        activity.mNeedsZBoost = true;
+        spyOn(taskDisplayArea.mSurfaceAnimator);
+
+        mDisplayContent.assignChildLayers(mTransaction);
+
+        assertThat(activity.needsZBoost()).isTrue();
+        assertThat(taskDisplayArea.needsZBoost()).isFalse();
+        verify(taskDisplayArea.mSurfaceAnimator, never()).setLayer(eq(mTransaction), anyInt());
+    }
+
     @Test
     public void testStackPositionChildAt() {
         // Test that always-on-top stack can't be moved to position other than top.