Add docker-engine feature flag for docker-engine w/ Ubuntu distro

[CecileRobertMichon]

What this PR does / why we need it: Deployments w/ GPU nodes in sovereign clouds need to install docker-engine without VHD as Moby is not compatible w/ GPU and AKS VHD is not yet available in sovereign clouds.

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:

If applicable:

• documentation
• unit tests
• tested backward compatibility (ie. deploy with previous version, upgrade with this branch)

Release note:

[jackfrancis]

/lgtm

[codecov]

Codecov Report

Merging #47 into master will increase coverage by 0.03%.
The diff coverage is 75%.

@@            Coverage Diff             @@
##           master      #47      +/-   ##
==========================================
+ Coverage   52.41%   52.44%   +0.03%     
==========================================
  Files          91       91              
  Lines       12792    12801       +9     
==========================================
+ Hits         6705     6714       +9     
- Misses       5479     5481       +2     
+ Partials      608      606       -2

[jackfrancis]

/lgtm

[acs-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CecileRobertMichon, jackfrancis

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