Disable WriteUnPrepared stress tests (#5315)

Summary:
They are kind of flaky at the moment. Will re-enable it when flakiness is fixed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5315

Differential Revision: D15382744

Pulled By: maysamyabandeh

fbshipit-source-id: 8b2f9d81a4bb34bfd51481727a682d5cd063c5e3

utilities/transactions/transaction_test.cc

@@ -79,11 +79,7 @@ INSTANTIATE_TEST_CASE_P(
         std::make_tuple(false, false, WRITE_PREPARED, kOrderedWrite, false),
         std::make_tuple(false, false, WRITE_PREPARED, kOrderedWrite, true),
         std::make_tuple(false, true, WRITE_PREPARED, kOrderedWrite, false),
-        std::make_tuple(false, true, WRITE_PREPARED, kOrderedWrite, true),
-        std::make_tuple(false, false, WRITE_UNPREPARED, kOrderedWrite, false),
-        std::make_tuple(false, false, WRITE_UNPREPARED, kOrderedWrite, true),
-        std::make_tuple(false, true, WRITE_UNPREPARED, kOrderedWrite, false),
-        std::make_tuple(false, true, WRITE_UNPREPARED, kOrderedWrite, true)));
+        std::make_tuple(false, true, WRITE_PREPARED, kOrderedWrite, true)));
 #endif  // ROCKSDB_VALGRIND_RUN
 
 TEST_P(TransactionTest, DoubleEmptyWrite) {