AliYun: Enable platform identification and enable by default.
AliYun cloud platform is now identifying themselves by setting the dmi
product id to the well known value "Alibaba Cloud ECS". The changes here
identify that properly in tools/ds-identify and in the DataSourceAliYun.
Since the 'get_data' for AliYun now identifies itself correctly, we can
enable AliYun by default.
disk_setup: udev settle before attempting partitioning or fs creation.
This attempts to use udevadm settle to wait until devices have been
fully "realized". If a device exists, there may still be events in
the udev queue that would create its partition table entries.
We need to wait until those have been processed also.
The instance-level SSH key was named 'sshKeys' and now is 'ssh-keys'.
The project-level SSH key attribute has not changed so is intentionally
not changed here.