A Nassau park may soon bear the name of Luis G. Alvarez, the Oceanside man whose sacrifice after one of the country’s darkest days and dedication to fellow 9/11 first responders despite terminal cancer drew the admiration of the nation he served. Nassau County Executive Laura Curran filed a resolution Tuesday to rename Terrell Avenue Park in Oceanside after one of the village’s most revered residents, calling the retired New York Police Department bomb squad detective a “champion” for the men and women who responded to the Sept. 11, 2001 terrorist attacks on the World Trade Center.