Fix failing unit tests for the new ipv6 ops file

[Milena-Encheva]

Please take a moment to review the questions before submitting the PR

🚫 We only accept PRs to develop branch. If this is an exception, please specify why 🚫

This PR is pushed against develop branch.

WHAT is this change about?

Adding line in the experimental_test/operations.yml in order to fix the failure in the unit tests.

Please provide any contextual information.

Missed the tests here:
#1253

Has a cf-deployment including this change passed cf-acceptance-tests?

• YES
• NO

Does this PR introduce a breaking change? Please take a moment to read through the examples before answering the question.

• YES - please choose the category from below. Feel free to provide additional details.
• NO

Types of breaking changes:

1. causes app or operator downtime
2. increases VM footprint of cf-deployment - e.g. new jobs, new add ons, increases # of instances etc.
3. modifies, deletes or moves the name of a job or instance group in the main manifest
4. modifies the name or deletes a property of a job or instance group in the main manifest
5. changes the name of credentials in the main manifest
6. requires out-of-band manual intervention on the part of the operator
7. modifies the ops-file path, changes the type, changes the values or removes ops-files from the following folders
   • ./operations/ or ./operations/experimental
   • ./addons
   • ./backup-and-restore/

If you're promoting an experimental Ops-file (or removing one), Please follow the Ops-file workflows.

Ops files changes in the following folders are considered as NON BREAKING CHANGES
./community, ./example-vars-files, ./test

How should this change be described in cf-deployment release notes?

Something brief that conveys the change and is written with the persona (Alana, Cody...) in mind. See previous release notes for examples.

Does this PR introduce a new BOSH release into the base cf-deployment.yml manifest or any ops-files?

• YES - please specify
• NO

Does this PR make a change to an experimental or GA'd feature/component?

• experimental feature/component
• GA'd feature/component

Please provide Acceptance Criteria for this change?

Please specify either bosh cli or cf cli commands for our team (and cf operators) to verify the changes.

Few examples

1. For a PR with a new job in the manifest, bosh instances can verify the job is running after upgrade. You can provide additional commands to verify the job is running as specified.
2. For a PR with new variables, bosh variables | grep <var-name> command can verify the variable exists. This is the simplest varification but you can also provide additional commands to test that the variable holds the desired value.

What is the level of urgency for publishing this change?

• Urgent - unblocks current or future work
• Slightly Less than Urgent

Tag your pair, your PM, and/or team!

@jochenehret