Use currentUserId for showForAllUsers tasks in TaskInfo

Similar to root tasks, let the userId reflect the current user otherwise
TaskInfo.userId will always reflect the userId of the user for which it
was initially created, even though it could now be running for a
different user.

Flag: com.android.window.flags.apply_desk_activation_on_user_switch
Bug: 430988310
Test: DesktopWallpaperActivity task's info or transition change info
shows the current user id even after switch

Change-Id: Ie836c57f31b82f0610dc55eb79fefe64eef1d1d0