Test: extend hash based routing test with hash_balance in manifest

[Mrizwanshaik]

Are you submitting this PR against the develop branch?

Yes

What is this change about?

The hash based issue discussed in the issue#585 is fixed via PR#586. This PR will extend the tests with introducing hash_balance in manifest and add an "is reachable" assertion under the hash context.

Please provide contextual information.

Issue: cloudfoundry/routing-release#585
routing-release PR: cloudfoundry/routing-release#586

What version of cf-deployment have you run this cf-acceptance-test change against?

Please check all that apply for this PR:

• introduces a new test --- Are you sure everyone should be running this test?
• changes an existing test
• requires an update to a CATs integration-config

Did you update the README as appropriate for this change?

• YES
• N/A

If you are introducing a new acceptance test, what is your rationale for including it CATs rather than your own acceptance test suite?

CATs should validate common operator workflows.
CATs is not a regression test suite.
CATs is run by every component team to validate their releases before promotion.

How many more (or fewer) seconds of runtime will this change introduce to CATs?

N/A

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!

@b1tamara

[jochenehret]

I assume that this test needs routing-release > 0.393.0 ?

Update: The test fails with routing-release 0.393.0, but passes with a dev release. So we'll wait for the next routing-release to be shipped before merging this PR.

Update 2: routing-release v0.394.0 is available, but cf-deployment validation is currently blocked and so this release is not yet merged into the cf-deployment release-candidate branch. CATs validate against this cf-d branch. As soon as the pipeline is unblocked we can merge this PR.