Your problem has more than 2 possible solutions.
1 create a file where you put the fix, name it as a php file for example fix.php, position it in some directory of your project and include it where you are going to use it with an include_once instruction 'path_to_file'
The 2nd option is to save the array data as a json in a file and then read the file, and decode the json.
In the first option, your fix file would look like:
<?php
$contentTypeArray=array(
1 => 'TEXTO',
2 => 'PDF',
3 => 'PPT',
4 => 'AUDIO',
5 => 'VIDEO',
6 => 'HTML',
);
And where you want to use it, you just have to put it at the beginning of the file
include_once 'ruta_al_fichero.php';
and you can use it as if you had declared it in this same file, with the same variable name
The second option would have to save your arrangement like a json
$fichero = fopen("ruta_donde_voy_a_guardar_el_archivo","w+");
$fichero->write($fichero, json_encode($mi_arreglo));
fclose($fichero);
Now if you want to read it you should load it from the route where you stored it
$ruta = "ruta_donde_guardastes_el_archivo";
$fichero = fopen($ruta,"r");
$contenido = fread($fichero,filesize($ruta));
//Ya en mi_arreglo tienes el arreglo original
$mi_arreglo = json_decode($contenido);