Merge "BrightnessTracker: getRootTaskInfoOnDisplay" into main

package com.android.server.display;

import static android.app.WindowConfiguration.ACTIVITY_TYPE_UNDEFINED;

import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;

import android.annotation.Nullable;

import android.annotation.UserIdInt;

import android.app.ActivityManager;

        }

        public RootTaskInfo getFocusedStack() throws RemoteException {

            if (UserManager.isVisibleBackgroundUsersEnabled()) {

                // In MUMD (Multiple Users on Multiple Displays) system, the top most focused stack

                // could be on the secondary display with a user signed on its display so get the

                // root task info only on the default display.

                return ActivityTaskManager.getService().getRootTaskInfoOnDisplay(

                        WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_UNDEFINED,

                        Display.DEFAULT_DISPLAY);

            }

            return ActivityTaskManager.getService().getFocusedRootTaskInfo();

        }