And the curriculum is determined by the government, correct?

And the intent of banning smartphones is to force all students to pay more attention to that curriculum, correct?

Government is not socialism. Indoctrination is also not socialism. You seem to be conflating the authoritarian/libertarian axis with socialism/capitalism axis. It is authoritarian, it isn't socialist because there's nothing about it inherent to socialism even though yes it is happening within a socialist structure. I think the more accurate sentence is "This is an obnoxious kind of authoritarianism". For example you can have a very socialist, very libertarian governmental structure. Some individuals view libertarian and socialist as opposites but actually they can completely coexist. It just takes viewing both corporations and governments as structures limiting your individual liberty. This kind of authoritarian policy can happen in either a capitalist or socialist environment.