Fix odom pose

[kohtake]

While trying to run navigation using this repo, noticed the incorrect output value of /odom/raw and fixed it.

Output of odometry before modification:

$ ros2 topic echo /odom/raw
...
pose:
  pose:
    position:
      x: 2.0621076296018528e-19
      y: 2.996481448410523e+32
      z: 0.0
    orientation:
      x: 0.0
      y: 0.0
      z: 2.951125177563796e-10
      w: 1.0
...