give SSOT/SPOT on default field TEST_PATH to avoid DRY

[Pankraz76]

After creating the PR, please add a commit that adds a bullet-point under the [Unreleased] section of CHANGES.md, plugin-gradle/CHANGES.md, and plugin-maven/CHANGES.md which includes:

• a summary of the change
• either
  • a link to the issue you are resolving (for small changes)
  • a link to the PR you just created (for big changes likely to have discussion)

If your change only affects a build plugin, and not the lib, then you only need to update the plugin-foo/CHANGES.md for that plugin.

If your change affects lib in an end-user-visible way (fixing a bug, updating a version) then you need to update CHANGES.md for both the lib and all build plugins. Users of a build plugin shouldn't have to refer to lib to see changes that affect them.

This makes it easier for the maintainers to quickly release your changes :)

• use default field for default test path #2574

[Pankraz76]

@ideepak @nedtwigg kindly request your feedback.

[nedtwigg]

This does not reduce complexity in a meaningful way. It is okay for the string constant to be different in each test, there's no magic to its name.

I am not interested in stylistic cleanup PRs. If a PR changes lots of lines, it needs to either

• be a deep simplification (not superficial)
• add a significant new feature with a large end user base