MC-11063: Add Product to Cart, Backorder Allowed

- Fixed missing argument
- Added waitForPageLoad

Author: tomreece

app/code/Magento/Catalog/Test/Mftf/ActionGroup/AddProductToCartActionGroup.xml

@@ -12,6 +12,7 @@
             <argument name="product" defaultValue="product"/>
         </arguments>
         <amOnPage url="{{StorefrontProductPage.url(product.custom_attributes[url_key])}}" stepKey="goToProductPage"/>
+        <waitForPageLoad stepKey="waitForProductPage"/>
         <click selector="{{StorefrontProductPageSection.addToCartBtn}}" stepKey="addToCart"/>
         <waitForElementNotVisible selector="{{StorefrontProductActionSection.addToCartButtonTitleIsAdding}}" stepKey="waitForElementNotVisibleAddToCartButtonTitleIsAdding"/>
         <waitForElementNotVisible selector="{{StorefrontProductActionSection.addToCartButtonTitleIsAdded}}" stepKey="waitForElementNotVisibleAddToCartButtonTitleIsAdded"/>

app/code/Magento/Catalog/Test/Mftf/Test/AdminBackorderAllowedAddProductToCartTest.xml

@@ -44,6 +44,7 @@
         <waitForPageLoad stepKey="waitForCartLoad"/>
         <actionGroup ref="AssertStorefrontCheckoutCartItemsActionGroup" stepKey="assertProductItemInCheckOutCart">
             <argument name="productName" value="$$createProduct.name$$"/>
+            <argument name="productSku" value="$$createProduct.sku$$"/>
             <argument name="productPrice" value="$$createProduct.price$$"/>
             <argument name="subtotal" value="$$createProduct.price$$" />
             <argument name="qty" value="1"/>