Change camera info message to lower case (backport #1005) (#1007)

Change camera info message to lower case since message type had been
change in rolling and humble.
[](https://github.com/ros2/common_interfaces/blob/rolling/sensor_msgs/msg/CameraInfo.msg)<hr>This
is an automatic backport of pull request #1005 done by
[Mergify](https://mergify.com).

---------

Signed-off-by: Alejandro Hernández Cordero <[email protected]>
Co-authored-by: SFhmichael <[email protected]>
Co-authored-by: Alejandro Hernández Cordero <[email protected]>

camera_calibration/src/camera_calibration/camera_checker.py

@@ -164,9 +164,9 @@ def handle_monocular(self, msg):
             image_points = C
             object_points = self.mc.mk_object_points([self.board], use_board_size=True)[0]
             dist_coeffs = numpy.zeros((4, 1))
-            camera_matrix = numpy.array( [ [ camera.P[0], camera.P[1], camera.P[2]  ],
-                                           [ camera.P[4], camera.P[5], camera.P[6]  ],
-                                           [ camera.P[8], camera.P[9], camera.P[10] ] ] )
+            camera_matrix = numpy.array( [ [ camera.p[0], camera.p[1], camera.p[2]  ],
+                                           [ camera.p[4], camera.p[5], camera.p[6]  ],
+                                           [ camera.p[8], camera.p[9], camera.p[10] ] ] )
             ok, rot, trans = cv2.solvePnP(object_points, image_points, camera_matrix, dist_coeffs)
             # Convert rotation into a 3x3 Rotation Matrix
             rot3x3, _ = cv2.Rodrigues(rot)