[DO NOT MERGE][NPE] check RecentsView exists before using it

Bug: 162176024
Change-Id: I8fe2ed42836bd6645f600b223e81526840ead557
diff --git a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
index 2058a7f..3621658 100644
--- a/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
+++ b/quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskView.java
@@ -419,7 +419,10 @@
                             }
                         }, resultCallbackHandler);
             }
-            getRecentsView().onTaskLaunched(mTask);
+            RecentsView recentsView = getRecentsView();
+            if (recentsView != null) {
+                recentsView.onTaskLaunched(mTask);
+            }
         }
     }