Thread based Applications fail to build with -Og and CHIP Logging disabled

[adabreuti]

Problem

With the debug build enabled along with CHIP Progress logging disabled, GenericThreadStackManagerImpl_OpenThread.cpp fails to compile due to unused variables (-Werror=unused-but-set-variable):

This condition can be reproduced by setting the following within args.gni for a certain application build.
is_debug = false
chip_progress_logging = false

Proposed Solution

GenericThreadStackManagerImpl_OpenThread.cpp should be using ifdefs for CHIP_PROGRESS_LOGGING in order to wrap the unused variables.