feat: added missing test for elasticsearch reconciler

[Ankit152]

Which problem is this PR solving?

• Missing unit test for controllers/elasticsearch

Description of the changes

• Adds missing unit test for controllers/elasticsearch

How was this change tested?

• Tested locally make test-unit

Checklist

• [x] I have read https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
• [x] I have signed all commits
• [ ] I have added unit tests for the new functionality
• [ ] I have run lint and test steps successfully
  • for jaeger: make lint test
  • for jaeger-ui: yarn lint and yarn test