[Backport] 6305 - Resolved product custom option title save issue

[jignesh-baldha]

Original Pull Request

#15357
Resolved product custom option's title save issue when the title is set to zero.

Description:

Navigate Admin => Catalog => Products => Create New / Edit Product.

1. Go to customizable options tab and add any custom options with drop down option type.
2. Set zero(0) in the title field and click save the product.
3. Product will save successfully and store zero value as a title of the drop down option.

Fixed Issues (if relevant)

1. Can't save Customizable options #6305: Can't save Customizable options

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 @jignesh-baldha. Thank you for your contribution.
We will aim to release these changes as part of 2.1.16.
Please check the release notes for final confirmation.