Allow Apple Media Format Previews

Apple strikes again, this time with NC. To enable HEIC and other format previews in your NC installation, add the following to your config.php file:

'enabledPreviewProviders' => 
  array (
    0 => 'OC\\Preview\\PNG',
    1 => 'OC\\Preview\\JPEG',
    2 => 'OC\\Preview\\GIF',
    3 => 'OC\\Preview\\BMP',
    4 => 'OC\\Preview\\XBitmap',
    5 => 'OC\\Preview\\MP3',
    6 => 'OC\\Preview\\TXT',
    7 => 'OC\\Preview\\MarkDown',
    8 => 'OC\\Preview\\OpenDocument',
    9 => 'OC\\Preview\\Krita',
    10 => 'OC\\Preview\\HEIC',
    11 => 'OC\\Preview\\MP4',
  ),