Fix LogManager tests

Fix testMockGetProperty, testReset.

LogManager is a singleton class, however, the test generates multiple
instance of it using MockLogManger class which inherits
LogManager. addLocalLogger in LoggerContext class uses the singleton
instance(which ideally should be the only instance) for setting the
level of the logger which creates inconsistency in data. The change adds
compatibilitiy for the test to use MockLogManager.

Bug: 25861348

Change-Id: I98fa0883c4687180059abf995519e997c8fadddf
1 file changed