LANSING, Mich. — Attorneys for state officials charged in the Flint water investigation asked Michigan’s highest court Wednesday to upend the state’s one-man grand jury process that led to their cases being shuttled into court without a public trying of facts to determine probable cause. Several defendants were challenging the one-judge grand jury process on varying levels. But all of them warned the Michigan Supreme Court that the use of the secretive process in such a high profile case opens the door to increased use of the one-judge grand jury and would cultivate mistrust in the justice sys…