fix: let clang-tidy allow bool conversions in conditions (#3475)
fix: let clang-tidy allow bool conversions in conditions (#3475)

* fix: let clang-tidy allow bool conversions in conditions

See https://github.com/googleapis/google-cloud-cpp-spanner/pull/1377 for rationale.

googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp