PS_INSTALL_AUTO=1 does not add Rijndael keys to settings

Hello,

PS_INSTALL_AUTO=1 does not add Rijndael keys to the settings it seems.
Using image: prestashop/prestashop:1.6-7.2-apache

The following code is shown in the frontoffice and backoffice:

Warning: Use of undefined constant _RIJNDAEL_KEY_ - assumed '_RIJNDAEL_KEY_' (this will throw an Error in a future version of PHP) in /var/www/html/classes/Cookie.php on line 79

Warning: Use of undefined constant _RIJNDAEL_IV_ - assumed '_RIJNDAEL_IV_' (this will throw an Error in a future version of PHP) in /var/www/html/classes/Cookie.php on line 79

Warning: Use of undefined constant MCRYPT_RIJNDAEL_128 - assumed 'MCRYPT_RIJNDAEL_128' (this will throw an Error in a future version of PHP) in /var/www/html/classes/Rijndael.php on line 124

Warning: openssl_decrypt(): IV passed is only 7 bytes long, cipher expects an IV of precisely 16 bytes, padding with \0 in /var/www/html/classes/Rijndael.php on line 91

Deprecated: The each() function is deprecated. This message will be suppressed on further calls in /var/www/html/tools/smarty/sysplugins/smarty_internal_compilebase.php on line 75

Warning: openssl_encrypt(): IV passed is only 7 bytes long, cipher expects an IV of precisely 16 bytes, padding with \0 in /var/www/html/classes/Rijndael.php on line 52

Warning: Use of undefined constant MCRYPT_RIJNDAEL_128 - assumed 'MCRYPT_RIJNDAEL_128' (this will throw an Error in a future version of PHP) in /var/www/html/classes/Rijndael.php on line 124

My docker-compose file looks as follows:

version: '3.4'

networks:
  network:
    driver: bridge

volumes:
    db-data:
    app-data:

services:
  prestashop:
    image: prestashop/prestashop:1.6-7.2-apache
    ports:
      - "80:80"
    networks:
      - network
    depends_on:
      - db
    volumes:
      - ./prestashop:/var/www/html
    environment:
      ADMIN_MAIL: my@email.com
      ADMIN_PASSWD: password
      PS_DEV_MODE: 1
      PS_COUNTRY: NL
      PS_DOMAIN: localhost
      PS_ERASE_DB: 1
      PS_FOLDER_ADMIN: backoffice
      PS_FOLDER_INSTALL: install
      PS_HANDLE_DYNAMIC_DOMAIN: 1
      PS_INSTALL_AUTO: 1
      PS_LANGUAGE: en
      DB_SERVER: db
      DB_USER: prestashop
      DB_PASSWD: password

  db:
    image: mariadb:latest
    networks:
      - network
    volumes:
       - db-data:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: password
      MYSQL_DATABASE: prestashop
      MYSQL_USER: prestashop
      MYSQL_PASSWORD: password

Reproduce the issue with the prestashop/prestashop:1.6-7.2-apache image and PS_INSTALL_AUTO=1, then inspect the generated settings alongside classes/Cookie.php and classes/Rijndael.php. Done means the Rijndael keys are present after automatic installation and the reported undefined-constant and encryption warnings no longer appear.