PHOENIX — A controversial Arizona law restricting how the public can film police faced its first legal challenge Tuesday with a lawsuit filed by the American Civil Liberties Union.The group’s Arizona chapter, joined by several Arizona news organizations, filed a petition in U.S. District Court. They argue the law criminalizes First Amendment freedoms.“This law is a violation of a vital constitutional right and will severely thwart attempts to build police accountability. It must be struck down before it …