MC-19451: Adapt functional tests to Elasticsearch

Author: Joan He

app/code/Magento/Checkout/Test/Mftf/Test/StorefrontCustomerCheckoutTest.xml

@@ -221,6 +221,10 @@
             <magentoCLI command="config:set payment/checkmo/allowspecific 1" stepKey="allowSpecificValue"  />
             <magentoCLI command="config:set payment/checkmo/specificcountry GB" stepKey="specificCountryValue" />
             <createData entity="Simple_US_Customer" stepKey="simpleuscustomer"/>
+
+            <!-- Perform reindex and flush cache -->
+            <magentoCLI command="indexer:reindex" stepKey="reindex"/>
+            <magentoCLI command="cache:flush" stepKey="flushCache"/>
         </before>
         <after>
             <deleteData createDataKey="createCategory" stepKey="deleteCategory"/>

app/code/Magento/Checkout/Test/Mftf/Test/StorefrontGuestCheckoutTest.xml

@@ -23,6 +23,10 @@
             <createData entity="ApiSimpleProduct" stepKey="createProduct">
                 <requiredEntity createDataKey="createCategory"/>
             </createData>
+
+            <!-- Perform reindex and flush cache -->
+            <magentoCLI command="indexer:reindex" stepKey="reindex"/>
+            <magentoCLI command="cache:flush" stepKey="flushCache"/>
         </before>
         <after>
             <actionGroup ref="logout" stepKey="adminLogout"/>