Unit test for GNOI is disabled

[ganglyu]

TestGNOI can't pass unit test. I have to skip this case to support unit test for PR.

I tried to enable READ_WRITE_MODE for unit test, test case for SystemTime can pass, but SonicShowTechsupport and SonicCopyConfig still does not work.
I think we need to fix the test cases for SonicShowTechsupport and SonicCopyConfig, and these test cases are introduced by management framework.