Options exists in the policy allow you to set the Automatic Agent upgrade option from the DCS manager via a Diagnostic Policy.
DCS Unix Agent
The option "agentupgradecheckenabled" can be edited (set/unset) using "Unix Agent Diagnostic Policy"
Enabling the automatic upgrade
Will set the option in agent.ini to Enable automatic upgrades
[agentupgrade]
agentupgradecheckenabled=1
Disabling the automatic upgrade
Will unset the option in agent.ini so automatic upgrades are disabled
[agentupgrade]
agentupgradecheckenabled=0