[v1.x] Add 1ES CI pipelines

[jviau]

Issue describing the changes in this PR

resolves #issue_for_this_pr

Pull request checklist

IMPORTANT: Currently, changes must be backported to the in-proc branch to be included in Core Tools and non-Flex deployments.

• Backporting to the in-proc branch is not required
  • Otherwise: Link to backporting PR
• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes should not be added to the release notes for the next release
  • Otherwise: I've added my notes to release_notes.md
• My changes do not need to be backported to a previous version
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• My changes do not require diagnostic events changes
  • Otherwise: I have added/updated all related diagnostic events and their documentation (Documentation issue linked to PR)
• I have added all required tests (Unit tests, E2E tests)

Additional information

This PR introduces the official, public, and integration-test build yaml files for the v1.x branch. Even though this branch is in servicing mode, we still need to ensure the build is compliant.

[jviau]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).