ftests: Add a test to validate cgclassify's systemd options (cgroup v2)

ftests: Add a test to validate cgclassify's systemd options (cgroup v2)

Add a test case to validate cgclassify tool's systemd options on cgroup
unified mode.

-----------------------------------------------------------------
Test Results:
        Run Date:                          Feb 05 07:43:23
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                                  Time (sec)
        ------------------------------------------------
        setup                                       0.00
        066-sudo-systemd_cgclassify-v2.py           7.57
        teardown                                    0.00
        ------------------------------------------------
        Total Run Time                              7.57

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>