Ensure the 'required' property gets saved for dynamic drop down fields

[eclarizio]

The required property wasn't being saved for dynamic drop down dialog fields. The user is able to manually change this value in the automate method, but since the option exists in the UI, they should be able to set it there as well, so this PR fixes that issue.

Ultimately, in the new dialog editor, this will be obsolete and the new editor does not have this issue.

https://bugzilla.redhat.com/show_bug.cgi?id=1492150

/cc @gmcculloug
@miq-bot add_label euwe/yes, fine/yes, bug
@miq-bot assign @h-kataria

@h-kataria If you think someone else should be assigned, please re-assign, thanks!

[miq-bot]

Checked commit eclarizio@de41bb4 with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
1 file checked, 0 offenses detected
Everything looks fine. 👍

[h-kataria]

changes look good

[simaishi]

Euwe backport (to manageiq repo) details:

 $ git log -1
commit 1a7396e2eb8c374f9592f6e96cce81c86f429d16
Author: Harpreet Kataria <[email protected]>
Date:   Mon Sep 18 19:41:49 2017 -0400

    Merge pull request #2185 from eclarizio/BZ1492150
    
    Ensure the 'required' property gets saved for dynamic drop down fields
    (cherry picked from commit ac02d7b602fc71702e4641f759c79ec14aee0436)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1495971

[chrispy1]

@miq-bot add_label blocker

[simaishi]

Fine backport details:

$ git log -1
commit 22c1f1f1f70f2e495e742d3b34415aea54ced69e
Author: Harpreet Kataria <[email protected]>
Date:   Mon Sep 18 19:41:49 2017 -0400

    Merge pull request #2185 from eclarizio/BZ1492150
    
    Ensure the 'required' property gets saved for dynamic drop down fields
    (cherry picked from commit ac02d7b602fc71702e4641f759c79ec14aee0436)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1496946