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

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

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

-----------------------------------------------------------------
Test Results:
        Run Date:                          Feb 05 14:38:30
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                             Time (sec)
        -------------------------------------------
        setup                                  0.00
        064-sudo-systemd_cgset-v2.py           2.33
        teardown                               0.00
        -------------------------------------------
        Total Run Time                         2.33

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
(cherry picked from commit 2c54492f27407119f7173a09c8fb2eec9d8f6b60)