Even though in target servers configuration i gave port as 443, host and SSLinfo enabled. Still in debug i am seeing the url as http:// instead of https://
I think that's a known bug in the DebugSession implementation.
If you change your TrustStore , you should see the TLS handshake fail. It would result in a 500 error. This would be evidence that HTTPS is actually being used, despite the DebugSesison showing http://
The team are working on a fix for this. I have no timeline for when that fix might be delivered.
BTW what version of Apigee are you using ?