Include volume_type for launch configuration ebs_block_device

[catrielgood]

Describe the solution you'd like
Currently the launch configuration does not include the "volume_type" variable for "ebs_block_device" . In this case, any ebs_block_devices passed are created as the default "gp2". Adding this variable will allow users to pass in their own desired volume type, like the more cost-efficient "gp3" type.

Additional code should just be the extra line:
volume_type = lookup(ebs_block_device.value, "volume_type", null)

Describe alternatives you've considered
We thought of simply downloading your module and making the desired changes but we do not wish to run the module locally and rather use yours as it gets updated. Not sure if there are any others. Would like to hear your opinions.

Additional context
Open to other suggestions.