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

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

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

-----------------------------------------------------------------
Test Results:
        Run Date:                          Feb 05 12:00:26
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                                              Time (sec)
        ------------------------------------------------------------
        setup                                                   0.00
        062-sudo-g_flag_controller_only_systemd-v2.py           2.25
        teardown                                                0.00
        ------------------------------------------------------------
        Total Run Time                                          2.25

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