[nrf noup] Add AppFactoryResetHandler

Add weak `AppFactoryResetHandler` to handle application specific
cleanup.

Signed-off-by: Adrian Gielniewski <adrian.gielniewski@nordicsemi.no>

Author: adigie

src/platform/Zephyr/ConfigurationManagerImpl.cpp

@@ -58,6 +58,11 @@
 #include <mpsl/mpsl_lib.h>
 #endif // CONFIG_SOC_FLASH_NRF_RADIO_SYNC_MPSL
 
+__weak bool AppFactoryResetHandler()
+{
+    return true;
+}
+
 namespace chip {
 namespace DeviceLayer {
 
@@ -238,8 +243,14 @@ void ConfigurationManagerImpl::DoFactoryReset(intptr_t arg)
     {
         ChipLogError(DeviceLayer, "Factory reset failed: %" CHIP_ERROR_FORMAT, err.Format());
     }
+
 #endif // CONFIG_CHIP_FACTORY_RESET_ERASE_SETTINGS
 
+    if (!AppFactoryResetHandler())
+    {
+        ChipLogError(DeviceLayer, "Factory reset failed, AppFactoryReset failed");
+    }
+
     PlatformMgr().Shutdown();
 }