[OTA] Reset instead of cancel when auto-apply is off (project-chip#16588

)

- By the time UpdateDownloaded is called, the download has already completed and there is no need to cancel the download
- Reset will make sure the state is transitioned to idle

examples/ota-requestor-app/linux/main.cpp

@@ -122,8 +122,8 @@ void CustomOTARequestorDriver::UpdateDownloaded()
     }
     else
     {
-        // Cancelling will put the state back to idle
-        gRequestorCore.CancelImageUpdate();
+        // Reset to put the state back to idle to allow the next OTA update to occur
+        gRequestorCore.Reset();
     }
 }