Fix TranslogTests#testStats (#66227)

If creating the latest translog file and retrieving a translog stats 
happen within the same millisecond, then the earliestLastModifiedAge
will be zero.

Closes #66092

server/src/test/java/org/elasticsearch/index/translog/TranslogTests.java

@@ -493,12 +493,13 @@ public void testStats() throws IOException {
         translog.getDeletionPolicy().setLocalCheckpointOfSafeCommit(randomLongBetween(3, Long.MAX_VALUE));
         translog.trimUnreferencedReaders();
         {
+            long lastModifiedAge = System.currentTimeMillis() - translog.getCurrent().getLastModifiedTime();
             final TranslogStats stats = stats();
             assertThat(stats.estimatedNumberOfOperations(), equalTo(4));
             assertThat(stats.getTranslogSizeInBytes(), equalTo(355L));
             assertThat(stats.getUncommittedOperations(), equalTo(0));
             assertThat(stats.getUncommittedSizeInBytes(), equalTo(firstOperationPosition));
-            assertThat(stats.getEarliestLastModifiedAge(), greaterThan(0L));
+            assertThat(stats.getEarliestLastModifiedAge(), greaterThanOrEqualTo(lastModifiedAge));
         }
     }