chore: cleanup README for non-istio service verification instructions, fixes RHOAIENG-5156

[dhirajsb]

Description

Cleanup README for enabling routes for non-istio model registry and it's service verification instructions Fixes RHOAIENG-5156

How Has This Been Tested?

Merge criteria:

• [X] The commits and have meaningful messages; the author will squash them after approval or will ask to merge with squash.
• [X] Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• [X] The developer has manually tested the changes and verified that the changes work