Braintree: test coverage

[dmytro-ch]

Description

This PR adds missing unit test for Magento\Braintree\Model\InstantPurchase\CreditCard\AvailabilityChecker class

Fixed Issues (if relevant)

N/A

Manual testing scenarios

N/A

[magento-engcom-team]

Hi @dmytro-ch. 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:

• @magento-engcom-team give me test instance - deploy test instance based on PR changes
• @magento-engcom-team give me {$VERSION} instance - deploy vanilla Magento instance

For more details, please, review the Magento Contributor Assistant documentation

[sidolov]

@magento-engcom-team combine 17456 17457

[magento-engcom-team]

Hi @sidolov. Thank you for your request. I'm working on combining the pull requests for you

[magento-engcom-team]

@dmytro-ch all pull requests have been successfully combined together:

• merged Braintree: Add unit test for PaymentAdditionalInformationProvider #17456: Braintree: Add unit test for PaymentAdditionalInformationProvider
• merged Braintree: Add unit test for LocaleResolver #17457: Braintree: Add unit test for LocaleResolver

[magento-engcom-team]

Hi @dmytro-ch. 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.