Set received_timestamp to system_clock::now() in message_info (backport #491)

[mergify[bot]]

• Relates https://github.com/ros2/rosbag2/pull/1641
• Fixes https://github.com/ros2/rosbag2/issues/1638

  ---

  This is an automatic backport of pull request #491 done by Mergify.

[clalancette]

Here's CI with this and https://github.com/ros2/rcl/pull/1157:

• Linux
• Linux-aarch64
• Windows

[clalancette]

All right, has multiple approvals and passes CI. Merging this one and https://github.com/ros2/rcl/pull/1157