Set dns domain on azure0 interface for ubuntu version >= 17

[tamilmani1989]

What this PR does / why we need it:

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #
This PR fixes cni issue with ubuntu 18 on addressing dns issues.
This fix enables resolving vmname from agent nodes

Special notes for your reviewer:

Release note:

[codecov]

Codecov Report

Merging #350 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #350   +/-   ##
=======================================
  Coverage   40.93%   40.93%           
=======================================
  Files          25       25           
  Lines        3518     3518           
=======================================
  Hits         1440     1440           
  Misses       1870     1870           
  Partials      208      208

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