Moving to HIPs community.
It's not currently an option. The minimal default size is 1MB, with an option to increae it to 999MB. If you tried to change the value to 0 for Activity log size in the Client UI / Troubleshooting policy, it will revert back to 1 when you save the policy. (refer to KB59968 in the McAfee Knowledge Base) You should file an FMR for this functionality.
If you don't want users to see your traffic, You can disable viewing of the HIP ClientUI tray icon.