Add e2e test for openshift vnet

[ritazh]

What this PR does / why we need it:
Add e2e test for Openshift with vnet

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

[codecov]

Codecov Report

Merging #2991 into master will increase coverage by 0.04%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2991      +/-   ##
==========================================
+ Coverage   50.71%   50.75%   +0.04%     
==========================================
  Files          97       97              
  Lines       14687    14682       -5     
==========================================
+ Hits         7448     7452       +4     
+ Misses       6539     6533       -6     
+ Partials      700      697       -3

Impacted Files	Coverage Δ
pkg/acsengine/defaults.go	83.56% <0%> (+0.03%)	⬆️
pkg/acsengine/transform/transform.go	63.17% <0%> (+0.12%)	⬆️
pkg/api/vlabs/validate.go	45.88% <0%> (+0.18%)	⬆️
pkg/acsengine/engine.go	62.59% <0%> (+0.2%)	⬆️

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[CecileRobertMichon]

/lgtm

[CecileRobertMichon]

/approve

[acs-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CecileRobertMichon

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[acs-bot]

New changes are detected. LGTM label has been removed.

[0xmichalis]

/hold

I think this should be a separate test vs updating the existing test.

@jim-minter @pweil-

[0xmichalis]

Fixes #2985

[0xmichalis]

We are flakying a lot on #2982

[jim-minter]

I agree this should be a separate test.
@ritazh please cc @jim-minter @Kargakis @pweil- on openshift-related PRs

[kwoodson]

@ritazh, could you rebase and fix the conflicts for this PR? Thanks!

[jim-minter]

@kwoodson this needs to be an additional test, not replacing the existing one - can you open a new PR based on Rita's work to take this forward?

[kwoodson]

@jim-minter @ritazh

I have added #3274 to take the place of this PR. Feel free to comment there.