LOS ANGELES — On the eve of his 25th birthday, Rams star receiver Puka Nacua said he was working on becoming a better person — and that if he continued on that journey the potential massive contract extension that appears to have stalled will take care of itself. Nacua on Thursday addressed reporters for the first time since checking into a Malibu rehab facility in March. Nacua sought help after a string of incidents, which included a December incident that led to a civil lawsuit. “Something that I feel like I’ve learned is, it’s OK to ask for support,” Nacua said after participating in an organized-team activity workout in Woodland Hills.…