Rename XYZ_NETWORK_MANAGER variable to NETWORK_MANAGER in test code

Resolves openbmc/openbmc-test-automation#1234

Change-Id: Ib02caa48d16046f514acbf32e99f717ea09ccf0d
Signed-off-by: manasarm <manashsarma@in.ibm.com>
5 files changed