configure registry in `pre` to use cloud sql db

What does this MR do?

This is part of https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/11800 and another attempt at !730 (merged) with the following differences

• registry.password.secret is set to registry-postgresql-password-v1 to match the actual secret name
• Inside secret registry-postgresql-password-v1 the password is stored with the key password instead of key secret, as this is what the helm chart defaults to expecting.

Author Check-list

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Reviewer Check-list

• Reviewed the diff jobs to confirm changes are as expected
• Are there changes shown in the diffs unassociated with this MR? - This may require a rebase or further investigation