Added network octet validation test cases.
Added network octet validation test cases.

Resolves openbmc/openbmc-test-automation#1773

Signed-off-by: Prashanth Katti <def1213b2b853506bc42999227c7ced90b83bfd2@in.ibm.com>
Change-Id: Ic3defe02898439de11cba0462e69c2bfbf5b78dd

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation