test_retry_query_result_cacheing_failed and test_retry_query_set_query_in_flight_failed are flaky

tests/custom_cluster/test_query_retries.py:761: in test_retry_query_result_cacheing_failed
    lambda: self.cluster.get_first_impalad().service.get_num_in_flight_queries() == 1)
tests/common/impala_test_suite.py:1128: in assert_eventually
    count, timeout_s, error_msg_str))
E   Timeout: Check failed to return True after 0 tries and 60 seconds

tests/custom_cluster/test_query_retries.py:775: in test_retry_query_set_query_in_flight_failed
    lambda: self.cluster.get_first_impalad().service.get_num_in_flight_queries() == 1)
tests/common/impala_test_suite.py:1128: in assert_eventually
    count, timeout_s, error_msg_str))
E   Timeout: Check failed to return True after 0 tries and 60 seconds

  @pytest.mark.execute_serially
  @CustomClusterTestSuite.with_args(
      impalad_args="--debug_actions=QUERY_RETRY_SET_RESULT_CACHE:FAIL",
      statestored_args="--statestore_heartbeat_frequency_ms=60000")
  def test_retry_query_result_cacheing_failed(self):
    """Test setting up results cacheing failed."""

    self.cluster.impalads[1].kill()
    query = "select count(*) from tpch_parquet.lineitem"
    self.hs2_client.set_configuration({'retry_failed_queries': 'true'})
    self.hs2_client.set_configuration_option('impala.resultset.cache.size', '1024')
    self.hs2_client.execute_async(query)
    self.assert_eventually(60, 0.1, 
        lambda: self.cluster.get_first_impalad().service.get_num_in_flight_queries() == 1)