Fix timer periodic test flakiness

Author: dlunch

java_runtime/tests/classes/java/util/test_timer.rs

@@ -89,12 +89,12 @@ async fn test_timer_periodic() -> Result<()> {
 
     let timer = jvm.new_class("java/util/Timer", "()V", ()).await?;
     let _: () = jvm
-        .invoke_virtual(&timer, "schedule", "(Ljava/util/TimerTask;JJ)V", (test_class.clone(), 0i64, 100i64))
+        .invoke_virtual(&timer, "schedule", "(Ljava/util/TimerTask;JJ)V", (test_class.clone(), 0i64, 50i64))
         .await?;
 
     let _: () = jvm.invoke_static("java/lang/Thread", "sleep", "(J)V", (500i64,)).await?;
     let run_count: i32 = jvm.get_field(&test_class, "runCount", "I").await?;
-    assert_eq!(run_count, 5);
+    assert!(run_count > 2);
 
     Ok(())
 }