ftests: Add a test for cgroup_get_cgroup()

ftests: Add a test for cgroup_get_cgroup()

Add a functional test to exercise cgroup_get_cgroup()

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Test Results:
        Run Date:                          Dec 20 22:41:28
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                              Time (sec)
        --------------------------------------------
        setup                                   0.00
        051-sudo-cgroup_get_cgroup.py           0.03
        teardown                                0.00
        --------------------------------------------
        Total Run Time                          0.03

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