FirmwareImage: Keep config extn in activate

• In Download() operate command a. if AutoActivate=true, then only use the provided KeepConfig value b. in case of KeepConfig not provided use default download_keep_config=1 c. if AutoActivate=false or not provided then ignore Keepconfig value, d. By default don't copy config
• In Activate() operate command a. Add a vendor extension for KeepConfig b. If KeepConfig not provided then use "1" as default keep config value