Merge "Avoid the scenario Where taskdisplayarea is null" into sc-v2-dev am: 3767ba9926

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15581985

Change-Id: Id7c3736efe945f323eb0618a56d57afbbe3e8280

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

@@ -1509,7 +1509,7 @@ class ActivityStarter {
         final Task targetTask = r.getTask() != null
                 ? r.getTask()
                 : mTargetTask;
-        if (startedActivityRootTask == null || targetTask == null) {
+        if (startedActivityRootTask == null || targetTask == null || !targetTask.isAttached()) {
             return;
         }