Remove the requirement that launch role must start with SCLaunch

[zipengw27]

Description of changes:

Remove the requirement that launch role must start with the prefix SCLaunch

Testing:

• Provision with an arbitrary launch role named TerraformExampleRole succeeds
• Update with an arbitrary launch role named TerraformExampleRole succeeds
• Terminate with an arbitrary launch role named TerraformExampleRole succeeds
• Parameter parsing with an arbitrary launch role named TerraformExampleRole succeeds