Clean up the mLastSentTaskInfos entry

mLastSentTaskInfos, A map maintains the relationship between task and
runningTaskInfo. RunningTaskInfo was put into the map during the
TaskOrganizerController#dispatchTaskInfoChanged, but never remove it.
This CL removes the entry while the task is vanished.

Bug: 199523354
Test: atest TaskOrganizerTest
            ShellTaskOrganizerTests
            PipTaskOrganizerTest
Change-Id: I55b1caff1ff3fe43db12350659f0a066ed4ef5dd

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

@@ -688,6 +688,7 @@ class TaskOrganizerController extends ITaskOrganizerController.Stub {
                     if (state != null) {
                         state.mOrganizer.onTaskVanished(task);
                     }
+                    mLastSentTaskInfos.remove(task);
                     break;
                 case PendingTaskEvent.EVENT_INFO_CHANGED:
                     dispatchTaskInfoChanged(event.mTask, event.mForce);