Only set test_attempt_start and test_attempt_duration if a test w…

…as run.

Fixes a defect in bazelbuild@db4c550 (commit db4c550) which leads to `TestResult` protobufs containing a default-value `Timestamp`. This `Timestamp` is a valid representation of the UNIX epoch. To ensure downstream consumers do not need to special-case this `Timestamp` we should take care not to produce this value unless a test actually starts/ends at the UNIX epoch.

PiperOrigin-RevId: 668155710
Change-Id: Iaf6fa56a5b572e1416cfda61b94328f7a7fb83bc

src/main/java/com/google/devtools/build/lib/analysis/test/TestAttempt.java

@@ -255,9 +255,13 @@ public BuildEventStreamProtos.TestResult asTestResult(BuildEventContext converte
     builder.setStatusDetails(statusDetails);
     builder.setExecutionInfo(executionInfo);
     builder.setCachedLocally(cachedLocally);
-    builder.setTestAttemptStart(Timestamps.fromMillis(startTimeMillis));
+    if (startTimeMillis != 0) {
+      builder.setTestAttemptStart(Timestamps.fromMillis(startTimeMillis));
+    }
     builder.setTestAttemptStartMillisEpoch(startTimeMillis);
-    builder.setTestAttemptDuration(Durations.fromMillis(durationMillis));
+    if (durationMillis != 0) {
+      builder.setTestAttemptDuration(Durations.fromMillis(durationMillis));
+    }
     builder.setTestAttemptDurationMillis(durationMillis);
     builder.addAllWarning(testWarnings);
     for (Pair<String, Path> file : files) {