Generally, installing a test cert as a Trusted Root is the preferred way. This hasn't changed since XP.
Problem with disabling security settings, or writing handling code inside your tests is you end up not testing the SSL setup. For example, say a page that loads in external assets that's http on an https page. You want the test to fail here, since the customer will see a security warning on a page that is designated as secure.
With installing a test cert into the Trusted Root certs, you can test the https experience closer to what the customer would experience on production.
Moderators, should this be moved to the LoadRunner forum?
Ramana, Chit-Chat is typically used for off topics stuff. You'll see links to forums that are specific to the tools and technologies and that is the place to post tool specific questions. Looks like you are new to the site - welcome to a great place to learn and share knowledge!!
SoCalGal - Defender of end user response times!