Save configurable product options after validation error

[swnsma]

Description

1. Fix issue with configurable product save.
2. Improve fix for issue Product images gets removed from "Images And Videos" after validation alert. #7372 - cover edge case.

Fixed Issues

1. Can't save attributes on a configurable product #13177: Can't save attributes on a configurable product
2. Product images gets removed from "Images And Videos" after validation alert. #7372: Product images gets removed from "Images And Videos" after validation alert.

Manual testing scenarios

Pre-conditions

1. Created configurable product with the options

Steps to reproduce

1. Go to Admin Panel.
2. Go to Product Edit form of Configurable product.
3. Remove value from 'Name' attribute and press 'Save'.
4. See js validation error.
5. Fill 'Name' attribute and press 'Save'.

Expected result

1. Product was saved

Actual result

1. Magento report will be shown.
2. After page reload, you will see session message 'Warning: array_filter() expects parameter 1 to be array, string given invendor/magento/module-configurable-product/Controller/Adminhtml/Product/Initialization/Helper/Plugin/Configurable.php on line 145

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-engcom-team]

Hi @swnsma. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

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[magento-engcom-team]

Hi @swnsma. Thank you for your contribution.
We will aim to release these changes as part of 2.2.7.
Please check the release notes for final confirmation.

Please, consider to port this solution to 2.3 release line.
You may use Porting tool to port commits automatically.