In this answer the following graph is displayed:
It shows two slight increases in altitude (after 1st peak g and at the end of the blackout). For me, it looks like zoom climbs (trading kinetic energy (velocity) for potential energy (altitude)) made to slow down the space craft, but I cannot find any evidence.
What is the purpose of these climbs? Is it to slow down the spacecraft? Is it a common maneuver used during reentry (i.e. is the Apollo spacecraft the only one performing such maneuver)?