MC-42443: Row Sub Total is not updated with new price when Price is updated through API

- Fixed the PR comments.
- Added the Integration test.

Author: devarul

app/code/Magento/Quote/Model/Product/Plugin/UpdateQuote.php

@@ -46,6 +46,8 @@ public function __construct(
     }
 
     /**
+     * Update the quote trigger_recollect column is 1 when product price is changed through API.
+     *
      * @param TierPriceStorageInterface $subject
      * @param $result
      * @param $prices

dev/tests/integration/testsuite/Magento/Quote/Model/Product/Plugin/UpdateQuoteTest.php

@@ -0,0 +1,70 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Quote\Model\Product\Plugin;
+
+use Magento\Quote\Model\ResourceModel\Quote as QuoteResource;
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\TestFramework\Quote\Model\GetQuoteByReservedOrderId;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Tests for update quote plugin.
+ *
+ * @magentoAppArea adminhtml
+ */
+class UpdateQuoteTest extends TestCase
+{
+    /**
+     * @var GetQuoteByReservedOrderId
+     */
+    private $getQuoteByReservedOrderId;
+
+    /**
+     * @inheritdoc
+     */
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $objectManager = Bootstrap::getObjectManager();
+        $this->getQuoteByReservedOrderId = $objectManager->get(GetQuoteByReservedOrderId::class);
+    }
+
+    /**
+     * Test to update the column trigger_recollect is 1 from quote table.
+     *
+     * @magentoDataFixture Magento/Checkout/_files/quote_with_simple_product_saved.php
+     * @return void
+     */
+    public function testUpdateQuoteRecollectAfterChangeProductPrice(): void
+    {
+        $quote = $this->getQuoteByReservedOrderId->execute('test_order_with_simple_product_without_address');
+        $this->assertNotNull($quote);
+        $this->assertFalse((bool)$quote->getTriggerRecollect());
+        $this->assertNotEmpty($quote->getItems());
+        $quoteItem = current($quote->getItems());
+        $product = $quoteItem->getProduct();
+
+        /** @var QuoteResource $quoteResource */
+        $quoteResource = $quote->getResource();
+        $quoteResource->markQuotesRecollect($product->getId());
+        /** @var AdapterInterface $connection */
+        $connection = $quoteResource->getConnection();
+        $select = $connection->select()
+            ->from(
+                $quoteResource->getTable('quote'),
+                ['trigger_recollect']
+            )->where(
+                "reserved_order_id = 'test_order_with_simple_product_without_address'"
+            );
+
+        $quoteRow = $connection->fetchRow($select);
+        $this->assertNotEmpty($quoteRow);
+        $this->assertTrue((bool)$quoteRow['trigger_recollect']);
+    }
+}