When attempting to make manual changes to the liagent.ini file in vRA, the changes are automatically reverted to their previous values.
This is an expected behaviour. The liagent.ini file cannot be modified manually in Aria Automation.
See the KB Changes to liagent.ini are constantly overwritten on Aria Automation and Aria Orchestrator for more information.
To filter events received by Aria Automation in Aria Operations for logs, you can use the Log Filtering functionality located under the Log Management page.
For more information, see the documentation: Add a Log Filter Configuration