chore: Preprend log names with java-logging

Author: lqiu96

google-cloud-logging/src/main/java/com/google/cloud/logging/testing/RemoteLoggingHelper.java

@@ -24,7 +24,6 @@
 import java.io.InputStream;
 import java.time.Duration;
 import java.time.Instant;
-import java.time.format.DateTimeFormatter;
 import java.util.UUID;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -95,14 +94,15 @@ public static RemoteLoggingHelper create() {
 
   /**
    * Formats a resource name for testing purpose. This method appends a random UUID to the provided
-   * name. Prepends the Log name with the current instant time to allow for stale logs to be easily
-   * found and removed.
+   * name. Prepends the Log name with the `java-logging` and the current instant time to allow for
+   * stale logs to be easily found and removed.
    *
-   * <p>Format: {Instant}_{name}_{UUID}
+   * <p>Format: java-logging_{INSTANT_IN_MILLIS}_{name}_{UUID}
    */
   public static String formatForTest(String name) {
-    String now = DateTimeFormatter.ISO_LOCAL_DATE.format(Instant.now());
-    return now + "_" + name + "_" + UUID.randomUUID().toString().substring(0, 8);
+    long nowInMillis = Instant.now().toEpochMilli();
+    return String.format(
+        "java-logging_%d_%s_%s", nowInMillis, name, UUID.randomUUID().toString().substring(0, 8));
   }
 
   private static RetrySettings retrySettings() {

google-cloud-logging/src/test/java/com/google/cloud/logging/BaseSystemTest.java

@@ -51,13 +51,14 @@ static void beforeClass() {
   @AfterAll
   static void afterClass() throws Exception {
     // Use a cutoff of a day based on the log name. Any logs that were created before the cutoff
-    // is from a previous invocation of the test and was unable to be properly deleted.
+    // is from a previous invocation of the test and was previously unable to be properly deleted.
     Page<String> logPage = logging.listLogs();
     for (String logName : logPage.iterateAll()) {
-      Instant cutoff = Instant.now().minus(1, ChronoUnit.DAYS);
-      String logCreateTimeString = logName.split("_")[0];
-      Instant logCreateTimeInstant =
-          (Instant) DateTimeFormatter.ISO_LOCAL_DATE.parse(logCreateTimeString);
+      if (!logName.startsWith("java-logging")) {
+        continue;
+      }
+      Instant cutoff = Instant.now().minus(6, ChronoUnit.HOURS);
+      Instant logCreateTimeInstant = Instant.ofEpochMilli(Long.parseLong(logName.split("_")[0]));
       if (logCreateTimeInstant.isBefore(cutoff)) {
         logging.deleteLog(logName);
       }