[nrf noup] Lock thread stack before factory reset

This commit fix a problem with thread activity interrupting factory reset.
This activity used to led to “Factory reset fail: -6”.
Writing to cleared nvm flash pages caused the problem.

Signed-off-by: Patryk Lipinski <patryk.lipinski@nordicsemi.no>

src/platform/Zephyr/ConfigurationManagerImpl.cpp

@@ -176,6 +176,7 @@ void ConfigurationManagerImpl::RunConfigUnitTest(void)
 void ConfigurationManagerImpl::DoFactoryReset(intptr_t arg)
 {
  ChipLogProgress(DeviceLayer, "Performing factory reset");
+ ThreadStackMgr().LockThreadStack();
 
 #ifdef CONFIG_CHIP_FACTORY_RESET_ERASE_NVS
  void * storage = nullptr;