[java-datastore][flaky test] datastore.it.ITE2ETracingTest: ITE2ETracingTest.deleteTraceTest:709->fetchAndValidateTrace:509->fetchAndValidateTrace

[zhumin8]

datastore.it.ITE2ETracingTest has been failing repeatedly in my pr #13600.

Here is log snippet from one of the failed runs. See details in full log

02:21:48:941 [ERROR]   ITE2ETracingTest.deleteTraceTest:709->fetchAndValidateTrace:509->fetchAndValidateTrace:475 Runtime Expected number of spans: 2, Actual number of spans: Trace NOT_FOUND
02:21:48:942 [ERROR]   ITE2ETracingTest.newTransactionReadTest:813->fetchAndValidateTrace:475 Runtime Expected number of spans: 4, Actual number of spans: [span_id: 2168163020973624314
name: "ITE2ETracingTest1782871953719"