School boards; student cell phone and smart device possession and use policies; prohibition. Amends the requirements for the student cell phone and smart device possession and use policies that each school board is required to develop and each public elementary and secondary school is required to implement pursuant to applicable law to require such policies to, except as provided in applicable law, prohibit student cell phone and smart device possession and use on school property from bell to bell. Current law only requires such policies to restrict student cell phone and smart device possession and use on school property from bell to bell.