make ros2 installation optional

Signed-off-by: Yuxuan Liu <[email protected]>

ansible/playbooks/universe.yaml

@@ -12,6 +12,12 @@
         [Warning] Should the ONNX model files and other artifacts be downloaded alongside setting up the development environment.
         Download artifacts? [y/N]
       private: false
+    - name: prompt_install_new_ros2
+      prompt: |-
+        [Warning] ROS 2 is required for Autoware. Please refer to https://docs.ros.org/en/humble/Installation.html for more information.
+        Install ROS 2? [y/N]
+      default: 'y'
+      private: false
   pre_tasks:
     - name: Verify OS
       ansible.builtin.fail:
@@ -36,8 +42,10 @@
   roles:
     # Autoware base dependencies
     - role: autoware.dev_env.ros2
+      when: prompt_install_new_ros2 == 'y'
     - role: autoware.dev_env.ros2_dev_tools
     - role: autoware.dev_env.rmw_implementation
+      when: prompt_install_new_ros2 == 'y'
     - role: autoware.dev_env.gdown
     - role: autoware.dev_env.build_tools