Pop superstar Justin Bieber announced on Friday the birth of his son, Jack Blues, with his model wife, Hailey, in a post that quickly garnered millions of likes on Instagram. “Welcome Home Jack Blues Bieber,” the Canadian singer posted, alongside a photo of the infant’s foot wrapped in a blanket, which has since received over 7 million likes. The celebrity couple had announced in May that they were expecting, sharing pictures of 27-year-old Hailey, a fashionista and businesswoman, cradling her belly. Justin Bieber, 30, first shot to global stardom as a teen pop sensation in 2009, producing hits such as…