Replace REQUEST_TIME in tests

Problem/Motivation

REQUEST_TIME is a deprecated global. There are several issues to remove it's use in core.

This issue is to remove it from just tests.

Proposed resolution

- Adjust KTB and BTB to add the service as a protected method
- Adjust KTB and BTB to add a protected variable for the request time
- This one of these throughout the tests

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet