An man who pleaded guilty to a string of armed robberies at pharmacies in the summer of 2022 has been sentenced to 11 years and six months in prison, the U.S. Attorney’s Office said. Charles Johnson, 28, of Irvington pleaded guilty in 2023 to three counts of Hobbs Act robbery and one count of brandishing a firearm while robbing three pharmacies where he demanded oxycodone and other prescription medications. He was sentenced Wednesday in Camden Federal court, authorities said. Johnson was accused by prosecutors of robbing three different pharmacies during June and July 2022. Authorities said Jo…