[New Form Builder] Label of a copied/duplicated field is being redefined when trying to save the form

• Type: Regression Bug
• Status: Closed
• Resolution: No Longer Reproducible
• Affects Version/s: Master
• Fix Version/s: None
• Component/s: Forms
• Labels: None
• Fix Priority: 4
• Last Working Version:
  Master
• Epic Link: [Forms 7.2] Migration to Metal-js
• Sprint: Forms_7.2_18

Summary:
Label of a copied/duplicated field is being redefined when saving the form.

 Steps to reproduce:

1. Go to System Settings > Forms > Enable the experimental interface;
2. Go to Content > Forms;
3. Add a Form;
4. Add a Text Field and edit its label (e.g.: "my field");
5. Duplicate the field and observe how the label is being created (e.g: "Copy of my field");
6. Save the Form and observe how that the label is redefined to the original field;**

Expected result:
Label of a copied/duplicated field should not be redefined when saving the form.

Actual result:
Label of a copied/duplicated field is being redefined when saving the form.

Reproducible in:
http://test-6-1-2/web/guest
master: e7583e4c172b3258515457f14ffadcb311fea361
Updated on: Tue Nov 6 09:26:09 2018 -0800