Hello,

There is an Idea in place for the same  -

https://www-secure.symantec.com/connect/ideas/extend-gup-functionality-distribute-auto-upgrade-install-packages-gup-process

However, Try "Product Update Settings" under Liveupdate Policies.

It Downloads Symantec Endpoint Protection product updates using a LiveUpdate server.

Downloads and installs client software updates automatically when users click LiveUpdate or when a scheduled LiveUpdate session runs. When disabled, prevents downloading and installing client software updates, even if another Symantec product runs LiveUpdate on the client computer.

If the LiveUpdate Settings policy specifies that clients download updates from a Symantec Endpoint Protection Manager or Group Update Provider, the updates are in the form of microdefs. If the LiveUpdate Settings policy specifies that clients download updates from a LiveUpdate server, the updates are in the form of MSP (patch) files.

This setting lets you control client software versions. When this setting is disabled, client software can only be manually updated. When the management server downloads and processes patches, it creates a microdef, which automatically appears as a new package. The new package appears in the Client Install Packages pane. You can then select the package, and use the Upgrade Groups with Package feature for your Windows clients. You must provide manual updates for Mac clients by using a third-party tool or by making the update package available for download on your network.

Also, check this Thread: 

https://www-secure.symantec.com/connect/forums/prerequisite-installing-sep-remotely#comment-7915541

Hope that helps!!