Hundreds of Canyon High School students walked out of campus in a demonstration to protest Immigration and Customs Enforcement on Tuesday morning.   Students held posters with messages and multicolored flags representing Latin America, as they walked from the campus on Nadal Street to the intersection of Soledad Canyon Road and Whites Canyon Road following their exit from school.   A William S. Hart Union High School District spokeswoman said the protest was entirely student-organized.  “Today,