tests: drop unit tests that only check default configuration values
tests: drop unit tests that only check default configuration values

Those tests do not add much value and only introduce burden when a
default value should be changed.

Change-Id: I32049399b16338996d6bef342c004d5de2446cf1

budnyjj/ofagent,budnyjj/ofagent,yamt/networking-ofagent,yamt/networking-ofagent-old3