Modify/rename script buildscripts/mount_ephemeral_drive.sh to buildscripts/mount_data_drive.sh as it's purpose is to mount /data, which most likely on an EBS-backed drive.

Modify buildscripts/launch_evergreen_ec2_instance.sh to provide the Windows device xvdf for EBS block device when creating an EC2 instance.

These changes are due to fact that the Windows attached storage is ephemeral. Powercycle testing requires storage (EBS) which is persistent through reboots and instance stop/start.