Summary:
Today, pg regress tests are not connecting through connection manager. The change is to incorporate changes to make pg regress tests run through connection manager.

In the java test code, if connection manager is enabled, `port` is being replaced by connection manager port in place of the pg port. The change is then propagated to the pg regress test code as earlier.
Jira: DB-12346

Test Plan:
Jenkins: test regex: .*TestPgRegress.*, enable connection manager

Test whether the pg regress tests are working as expected without connection manager. To verify that there is no regression in our test framework. I ran the pg regress tests with connection manager not enabled and verified that the tests are running successfully.

Reviewers: mkumar, rbarigidad, nkumar, asrinivasan, skumar, jason

Reviewed By: jason

Subscribers: svc_phabricator, yql, jason

Differential Revision: https://phorge.dev.yugabyte.com/D37129