feat: allow setting max_billed_bytes in BigQuery tools config

This will allow users to configure a limit to access in ADK tools on the charges for queries.

PiperOrigin-RevId: 831921163

tests/unittests/tools/bigquery/test_bigquery_query_tool.py

@@ -1826,3 +1826,26 @@ def test_execute_sql_no_truncation():
     # Check no truncation flag when fewer rows than limit
     assert result["status"] == "SUCCESS"
     assert "result_is_likely_truncated" not in result
+
+
+def test_execute_sql_maximum_bytes_billed_config():
+  """Test execute_sql tool respects maximum_bytes_billed from config."""
+  project = "my_project"
+  query = "SELECT 123 AS num"
+  statement_type = "SELECT"
+  credentials = mock.create_autospec(Credentials, instance=True)
+  tool_config = BigQueryToolConfig(maximum_bytes_billed=11_000_000)
+  tool_context = mock.create_autospec(ToolContext, instance=True)
+
+  with mock.patch("google.cloud.bigquery.Client", autospec=False) as Client:
+    bq_client = Client.return_value
+    query_job = mock.create_autospec(bigquery.QueryJob)
+    query_job.statement_type = statement_type
+    bq_client.query.return_value = query_job
+
+    execute_sql(project, query, credentials, tool_config, tool_context)
+
+    # Check that maximum_bytes_billed was called with config value
+    bq_client.query_and_wait.assert_called_once()
+    call_args = bq_client.query_and_wait.call_args
+    assert call_args.kwargs["job_config"].maximum_bytes_billed == 11_000_000