Added ubuntu18 AKS config for e2e test in ubuntu 18

[tamilmani1989]

What this PR does / why we need it:
Added ubuntu18 AKS config for doing e2e test in ubuntu 18

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

Special notes for your reviewer:

Release note:

[codecov]

Codecov Report

Merging #351 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #351   +/-   ##
=======================================
  Coverage   40.93%   40.93%           
=======================================
  Files          25       25           
  Lines        3518     3518           
=======================================
  Hits         1440     1440           
  Misses       1870     1870           
  Partials      208      208

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 18ebb28...3efe97b. Read the comment docs.