MC-22216: Tests for the customerCart Query

- added rollback fixture

Author: dthampy

dev/tests/integration/testsuite/Magento/Checkout/_files/active_quote_customer_not_default_store_rollback.php

@@ -6,3 +6,6 @@
 $objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
 $quote = $objectManager->create(\Magento\Quote\Model\Quote::class);
 $quote->load('test_order_1_not_default_store', 'reserved_order_id')->delete();
+
+require __DIR__ . '/../../../Magento/Customer/_files/customer_rollback.php';
+require __DIR__ . '/../../../Magento/Store/_files/second_store_rollback.php';