Update overheads for IPsec CBC tests

Updated to the values as seen in packet trace.
Even if VPP creates wrongly sized packets (compared to RFCs),
the overhead should correspond to the actual packet size present,
in order to correctly prevent linerate on DUT-DUT link.

The new overhead values are 62 (256SHA) and 78 (512SHA).
The GCM value is already correct, at 54 bytes, so density tests are ok.

- The lispgpe test is not updated, as it currently fails.
  We will update overhead there in (or after) 24578.

Change-Id: I5cc6920205f37ddc80e76804fabd90b67174addf
Signed-off-by: Vratko Polak <vrpolak@cisco.com>