Fix issue in Amazon warehouse exercise code that requires us to press Pause and Resume in order to begin the costmaps

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RViz crashes with the following relevant error log:

[lifecycle_manager-14] [INFO] [1623763988.819910346] [lifecycle_manager_navigation]: Activating bt_navigator
[bt_navigator-12] [INFO] [1623763988.820151127] [bt_navigator]: Activating
[lifecycle_manager-14] [INFO] [1623763988.820649555] [lifecycle_manager_navigation]: Activating robot_controller
[robot_controller-13] [WARN] [1623763988.820855865] [rcl_lifecycle]: No transition matching 3 found for current state unconfigured
[robot_controller-13] [ERROR] [1623763988.820880782] []: Unable to start transition 3 from current state unconfigured: Transition is not registered., at /tmp/binarydeb/ros-foxy-rcl-lifecycle-1.1.11/src/rcl_lifecycle.c:350
[lifecycle_manager-14] [ERROR] [1623763988.821223416] [lifecycle_manager_navigation]: Failed to change state for node: robot_controller
[lifecycle_manager-14] [ERROR] [1623763988.821246357] [lifecycle_manager_navigation]: Failed to resume nodes: aborting resume
[ERROR] [rviz2-5]: process has died [pid 3756, exit code -11, cmd '/opt/ros/foxy/lib/rviz2/rviz2 -d /home/trunc8d/shared-directory/exercise_ws/install/amazon_robot_bringup/share/amazon_robot_bringup/rviz/amazon_robot_default_view.rviz --ros-args -r __node:=rviz2'].