Trim CSV recordings

Remove the first lines of the recordings, as they arise from a static
vehicle, before the user engages the drive. It results in repeating
control commands, and the packet analyzer cannot determine which is the
first one for synchronization purposes.

Issue-Id: SCM-5774
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
Change-Id: Ib279e54b82fe89619c6d9b22a857dc87f6953b21