BED-4363 fix: adcs feature flag not in schema.sql

[mistahj67]

Description

• Moved the adcs feature flag to schema.sql where it should have been from this PR https://github.com/SpecterOps/BloodHound/pull/772
• Also bootstrapped it with updatable to false to be super safe

Motivation and Context

This PR addresses: BED-4363

Fixes a bug where adcs was updatable in bootstrapped environments due to order of migrations

How Has This Been Tested?

bootstrapped db to ensure it wasn't updatable

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Database Migrations

Checklist:

• [x] I have met the contributing prerequisites
  • Assigned myself to this PR
  • Added the appropriate labels
  • Associated an issue: https://github.com/SpecterOps/BloodHound/issues/672
  • Read the Contributing guide: https://github.com/SpecterOps/BloodHound/wiki/Contributing
• [x] I have ensured that related documentation is up-to-date
  • Open API docs
  • Code comments (GoDocs / JSDocs)
• [x] I have followed proper test practices
  • Added/updated tests to cover my changes
  • All new and existing tests passed