MAGETWO-86549: Unusual behavior with the persistent shopping cart after the session is expired

- Added observer to pass customer data from persistent session to checkout session
- Add automated test

Author: SeruyV

app/code/Magento/Persistent/Observer/SetCheckoutSessionPersistentDataObserver.php

@@ -66,8 +66,6 @@ public function __construct(
      *
      * @param \Magento\Framework\Event\Observer $observer
      * @return void
-     * @throws \Magento\Framework\Exception\NoSuchEntityException
-     * @throws \Magento\Framework\Exception\LocalizedException
      */
     public function execute(\Magento\Framework\Event\Observer $observer)
     {

app/code/Magento/Persistent/Test/Mftf/Test/StorefrontCheckShoppingCartBehaviorAfterSessionExpiredTest.xml

@@ -37,11 +37,11 @@
             <deleteData createDataKey="createCustomer" stepKey="deleteCustomer"/>
         </after>
         <!--Login as a Customer-->
-        <actionGroup ref="CustomerLoginOnStorefront" stepKey="signUpNewUser">
+        <actionGroup ref="CustomerLoginOnStorefront" stepKey="loginToStorefrontAccount">
             <argument name="customer" value="$$createCustomer$$"/>
         </actionGroup>
         <!-- Add simple product to cart -->
-        <actionGroup ref="AddSimpleProductToCart" stepKey="addProductToCart1">
+        <actionGroup ref="AddSimpleProductToCart" stepKey="addProductToCart">
             <argument name="product" value="$$createProduct$$"/>
         </actionGroup>
         <actionGroup ref="StorefrontOpenCartFromMinicartActionGroup" stepKey="goToShoppingCartFromMinicart"/>

app/code/Magento/Persistent/Test/Unit/Observer/SetCheckoutSessionPersistentDataObserverTest.php

@@ -88,8 +88,6 @@ protected function setUp()
      * Test execute method when session is not persistent.
      *
      * @return void
-     * @throws \Magento\Framework\Exception\LocalizedException
-     * @throws \Magento\Framework\Exception\NoSuchEntityException
      */
     public function testExecuteWhenSessionIsNotPersistent()
     {
@@ -113,8 +111,6 @@ public function testExecuteWhenSessionIsNotPersistent()
      * Test execute method when session is persistent.
      *
      * @return void
-     * @throws \Magento\Framework\Exception\LocalizedException
-     * @throws \Magento\Framework\Exception\NoSuchEntityException
      */
     public function testExecute()
     {