[DistributedLog] [tests] Flaky TestDynamicConfigurationFeatureProvider.testReloadFeaturesFromOverlay

I have seen this flaky test during 4.13.0rc0 validation.

***Describe the bug***

```
org.apache.distributedlog.feature.TestDynamicConfigurationFeatureProvider.testReloadFeaturesFromOverlay Time elapsed: 0.012 s <<< FAILURE!
java.lang.AssertionError: expected:<6000> but was:<5000>
at org.junit.Assert.fail(Assert.java:88)
at org.junit.Assert.failNotEquals(Assert.java:834)
at org.junit.Assert.assertEquals(Assert.java:645)
at org.junit.Assert.assertEquals(Assert.java:631)
at org.apache.distributedlog.feature.TestDynamicConfigurationFeatureProvider.testReloadFeaturesFromOverlay(TestDynamicConfigurationFeatureProvider.java:145)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)
at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.lang.Thread.run(Thread.java:748)

```