If set to 'auto', Bazel reruns a test if and only if: (1) Bazel detects changes in the test or its dependencies, (2) the test is marked as external, (3) multiple test runs were requested with --runs_per_test, or(4) the test previously failed. If set to 'yes', Bazel caches all test results except for tests marked as external. If set to 'no', Bazel does not cache any test results.