Enable detailed test output and flakiness check

Instruct Bazel to check for flakiness when executing tests
and display as a result:
- the output of the failed flaky test
- detailed report of the test results

Change-Id: I0c90b66870558488f773ce22d896de75e5cc0229
diff --git a/roles/bazelisk-build/tasks/main.yaml b/roles/bazelisk-build/tasks/main.yaml
index b16cb42..c06e0af 100644
--- a/roles/bazelisk-build/tasks/main.yaml
+++ b/roles/bazelisk-build/tasks/main.yaml
@@ -9,7 +9,7 @@
 - name: Run bazelisk test
   when: "bazelisk_test_targets != ''"
   shell: |
-    {{ bazelisk_executable }} test --java_toolchain=//tools:error_prone_warnings_toolchain {{ bazelisk_test_targets }}
+    {{ bazelisk_executable }} test --java_toolchain=//tools:error_prone_warnings_toolchain --test_output=errors --test_summary=detailed --flaky_test_attempts=3 {{ bazelisk_test_targets }}
   args:
     executable: /bin/bash
     chdir: "{{ zuul_work_dir }}"