Summary:
Original commit: d9ea0010e777dc21b19af62f8dffcf5ee5a46a15 / D42220
Call `SetSslConf` on the initdb conf so that the proper cret dir path is sent to initdb in secure clusters.

Fixes #26228
Jira: DB-15577

Test Plan: Jenkins

Reviewers: nikhil

Reviewed By: nikhil

Subscribers: ybase, yql

Differential Revision: https://phorge.dev.yugabyte.com/D42228