[Backport] Doesn't work if use date as condition for Catalog Price Rules

[mage2pratik]

Original Pull Request

#16855

Description

Fix following issue:
Doesn't work if use date as condition for Catalog Price Rules.

Manual testing scenarios

1. This problem happened when I go to Admin Panel -> MARKETING -> Catalog Price Rule,
   add or edit a Rule, then if use date as a condition, that condition doesn't work.

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)

[sidolov]

Hi @mage2pratik , due to changes in Magento Code Contributions Guide we can't accept such Pull Requests to 2.1 release line. We can accept fixes for known bugs only.
Thank you!