agent/acs/handler/refresh_credentials_handler.go
func validRoleType(roleType string) bool {
	switch roleType {
	case credentials.ApplicationRoleType:
		return true
	case credentials.ExecutionRoleType:
		return true
	default:
		return false
	}
}
func validRoleType(roleType string) bool {
	switch roleType {
	case credentials.ApplicationRoleType:
		return true
	case credentials.ExecutionRoleType:
		return true
	default:
		return false
	}
}
// validRoleType returns false if the RoleType in the acs refresh payload is not
// one of the expected types. TaskApplication, TaskExecution