Use existing BUILD files for test-related tools.

Allowlist BUILD files of test-related tools so that they appear in the final bp2build workspace. This is required for Bazel test rules that are dependent on these projects.

Test: b build //prebuilts/runtime/... //tools/asuite/atest:atest-tradefed  //tools/asuite/atest/bazel/reporter/...
Change-Id: Ie34658706efe6ca7657c935528df8daef61bfc0c