A former janitor was sentenced to federal prison for smuggling methamphetamine to inmates at San Quentin Rehabilitation Center, prosecutors said Friday. A former San Quentin Rehabilitation Center janitor, Keith Randle, 57, of Vallejo, California, was sentenced to 37 months in federal prison for smuggling methamphetamine, marijuana, and tobacco to inmates in a years-long prison contraband and bribery operation involving more than $100,000 in ille…