Warner Bros.’ “Black Adam” opened with an estimated €67 million, according to studio estimates Sunday, handing Dwayne Johnson his biggest box-office weekend as a leading man and launching the D.C. Comics character he spent a decade to bring to the big screen. “Black Adam” was a €200-million bid to upset the power balance in a DC Extended Universe dominated by the likes of Batman, Wonder Woman and Superman. The €67 million debut fell well shy of that stratosphere, even with the considerable draw of Johnson acting in his first superhero movie. Still, “Black Adam” managed the highest opening week…