test(bigquery): add ITBigQueryTest integration tests for queryArrow

[jinseopkim0]

This PR adds integration tests verifying the queryArrow client API against the live BigQuery service.

It tests single-page and multi-page Arrow stream consumption, validating row counts and VectorSchemaRoot iteration over live queries.

[gemini-code-assist]

Code Review

This pull request adds integration tests to verify query results in Arrow format. Specifically, it introduces testQueryResultsFormatArrow and testQueryResultsFormatArrowMultiPage in ITBigQueryTest.java to validate both single-page and multi-page query results using ArrowQueryResult and VectorSchemaRoot. I have no feedback to provide as there are no review comments.

[lqiu96]

added a small comment

[gemini-code-assist]

Code Review

This pull request introduces integration tests to verify BigQuery queries using the Arrow results format, specifically testing single-page and multi-page results. The review feedback suggests strengthening the assertions in the single-page test by validating the schema and actual values within the VectorSchemaRoot, rather than only checking the row count.

[gemini-code-assist]

To ensure the integrity of the data returned via the Arrow format, consider validating the schema and the actual values within the VectorSchemaRoot. Currently, the test only validates the row count, which could pass even if the data itself is corrupted or incorrectly mapped.

      for (VectorSchemaRoot root : result) {
        batchCount++;
        totalRows += root.getRowCount();
        assertEquals(1, root.getRowCount());
        assertNotNull(root.getSchema().findField("id"));
        assertNotNull(root.getSchema().findField("name"));
        assertNotNull(root.getSchema().findField("ts"));
        assertEquals(1L, root.getVector("id").getObject(0));
        assertEquals("hello", root.getVector("name").getObject(0).toString());
      }