Add mockito configuration to support static mocking without mockito-i…

[pabloem]

…nline

Following the tips here: https://stackoverflow.com/questions/65986197/difference-between-mockito-core-vs-mockito-inline

Removing extra dep added here: #17753

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Choose reviewer(s) and mention them in a comment (R: @username).
• Add a link to the appropriate issue in your description, if applicable. This will automatically link the pull request to the issue.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

To check the build health, please visit https://github.com/apache/beam/blob/master/.test-infra/BUILD_STATUS.md

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI.

[ryanthompson591]

Seems fine, but will this still fix the build problem with importing mockito in BeamModulePlugin.groovy?

[pabloem]

hm this seems to definitely have broken something, hah.