remote DB for remote servers with Aegir
You're getting the error "MySQL server has gone away". Usually when this happens during Drupal installation, it's related to MySQL's max_allowed_packet setting. I'd recommend bumping that value up to 32MB. The process for changing that value on Amazon RDS is detailed here: https://survivalguides.wordpress.com/2012/02/02/change-the-max_allowed_packet-amazon-rds/