As the Doc ID: 1071895.1 confirms that the "cookie-http-only" property supported from Weblogic 9.2 MP4.
Does it mean that the same functionality supported from Peopletools 8.49 running on Weblogic 9.2 MP4 as well.
No: Weblogic 9.2 MP$ support this property "cookie-http-only" but peopletools 8.49 doesn't support this feature.
The property "cookie-http-only" is supported from peopletools 8.50 onwards.