Resolve "Add istio mTLS for ESO"

General MR

Summary

Deployed with istio, permissions are set to PERMISSIVE. This needs to be set to STRICT, unless it breaks functionality.

Relevant logs/screenshots

Example test override:

istio:
  enabled: true
packages:
  externalSecrets:
    enabled: true
    git:
      repo: https://repo1.dso.mil/big-bang/apps/sandbox/external-secrets
      tag: null
      branch: 10-add-istio-auth-policy
      path: chart
    values:
      bbtests:
        enabled: true
      istio:
        enabled: true
        mtls:
        # Available value PERMISSIVE or STRICT
          mode: STRICT

Linked Issue

issue

Upgrade Notices

• Added istio mTLS policies
• Enable helm test with istio enabled

Closes #10 (closed)