Use topComponent to get package name

task.topActivity can be null

Fixes: 226232720
Test: manual
Change-Id: I7d0c928871d01402bf41bc96514aae7854045baf
diff --git a/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java b/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java
index f3ad0f6..ee69fc3 100644
--- a/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java
+++ b/quickstep/src/com/android/quickstep/util/SplitSelectStateController.java
@@ -111,7 +111,7 @@
         if (mInitialTaskIntent != null) {
             fillInIntent = new Intent();
             if (TextUtils.equals(mInitialTaskIntent.getComponent().getPackageName(),
-                    task.topActivity.getPackageName())) {
+                    task.getTopComponent().getPackageName())) {
                 fillInIntent.addFlags(Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
             }
         } else {