Destroy ActivityRecord when it is removed from the hierarchy

When activity is finishing from back, it may be added to the
ActivityTaskSupervisor#mFinishingActivities and wait for the resume
activity IDLE before destroy.

However, TaskFragmentOrganizer will be notified to apply WCT to delete
the TaskFragment that has no running activity before that is done. It
will cause the activity removed from the hierarchy before the destroy is
called.

Fix: 195454840
Test: Verify with Sidecar + Demo app
Change-Id: I60d9217d061ee53421661bde496b5fb320f01b87

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

@@ -3687,7 +3687,7 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
 
     @Override
     void removeImmediately() {
-        if (!finishing) {
+        if (!isState(DESTROYING, DESTROYED)) {
             // If Task#removeImmediately is called directly with alive activities, ensure that the
             // activities are destroyed and detached from process.
             destroyImmediately("removeImmediately");

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

@@ -1615,6 +1615,21 @@ public class ActivityRecordTests extends WindowTestsBase {
         assertFalse(wpc.hasActivities());
     }
 
+    @Test
+    public void testRemoveImmediatelyWithFinishingActivity() throws RemoteException {
+        final ActivityRecord activity = createActivityWithTask();
+        final WindowProcessController wpc = activity.app;
+        activity.makeFinishingLocked();
+        assertTrue(activity.finishing);
+
+        activity.getTask().removeImmediately("test");
+
+        verify(mAtm.getLifecycleManager()).scheduleTransaction(any(), eq(activity.appToken),
+                isA(DestroyActivityItem.class));
+        assertFalse(wpc.hasActivities());
+        assertEquals(DESTROYING, activity.getState());
+    }
+
     @Test
     public void testRemoveFromHistory() {
         final ActivityRecord activity = createActivityWithTask();