dac_start_destroy: Add case to cover security_default_confined as 0

Add case for cover unconfined DAC testing, 2 cases added to cover bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1105939

New cases with 'security_default_confined = 0' and seclabel as:
<seclabel type='none' model='dac' relabel='yes'/>

Signed-off-by: Wayne Sun <gsun@redhat.com>