Variables from OCIL defined in rule.yml are not being expanded

#### Description of problem:
Variables used in OCIL section are not being expanded

linux_os/guide/system/accounts/accounts-physical/screen_locking/smart_card_login/configure_opensc_card_drivers/rule.yml:
```
ocil: |-
To verify that is configured
as the smart card driver, run the following command changing ARCH for
the architecture of your operating system:

$ grep card_drivers /etc/opensc-ARCH

The output should return something similar to:

card_drivers = ;

```

#### SCAP Security Guide Version:
0.1.44

#### Operating System Version:

#### Steps to Reproduce:

1. cat build/ssg-rhel7-ds.xml | grep -A 2 -B 2 "card_drivers = ;"
2.
3.
4.

#### Actual Results:

$ grep card_drivers /etc/opensc-ARCH
The output should return something similar to:
card_drivers = ;
Is it the case that the smart card driver is not configured correctly?

...

#### Expected Results:
$ grep card_drivers /etc/opensc-ARCH
The output should return something similar to:
card_drivers = 300;
Is it the case that the smart card driver is not configured correctly?

...

#### Addition Information/Debugging Steps: