School Bus Safety; Authorizing school districts to install and operate side stop signal arm enforcement systems on school buses; authorizing school districts to contract with a private vendor or manufacturer to provide side stop signal arm enforcement systems; providing that recorded images evidencing a violation of this act shall be admissible in any judicial or administrative proceeding for a certain purpose; specifying requirements of and prohibitions on the use of recorded video and still images captured by the side stop signal arm enforcement system, etc.