(main) Do not prompt on configuration file update

(main) Do not prompt on configuration file update

When updating configuration file, apt by default prompt the user for the
action to perform.  Since we are running in a non-interactive context,
skip these prompts:

  * `--force-confdef` ensure the configuration file is replaced by a
    newer version in the package if the previous package default
    configuration file was not modified;
  * `--force-confold` keep the configuration file as it is if it has
    been modified compared to the one shipped in the previous version of the
    package.