Remove mock.patch.stop from tests that inherit from BaseTestCase

The tests that inherit from BaseTestCase don't need to stop their
patches, since this is already done in the base class

Change-Id: Ibb1183e521686d6e948046997b32f4044d91d9e7
Closes-bug: #1305656
Merge "Remove mock.patch.stop from tests that inherit from BaseTestCase"