MAGETWO-94269: PayPal advanced payments won't process payment due to an incorrect redirect after a silent post

- address code review comments

Author: Joan He

app/code/Magento/Paypal/Controller/Payflow/ReturnUrl.php

@@ -68,7 +68,7 @@ public function execute()
             if ($order->getIncrementId()) {
                 if ($this->checkOrderState($order)) {
                     $redirectBlock->setData('goto_success_page', true);
-                    $this->_eventManager->dispatch('checkout_success', ['order' => $order]);
+                    $this->_eventManager->dispatch('paypal_checkout_success', ['order' => $order]);
                 } else {
                     if ($this->checkPaymentMethod($order)) {
                         $gotoSection = $this->_cancelPayment((string)$this->getRequest()->getParam('RESPMSG'));

app/code/Magento/Paypal/Test/Unit/Controller/Payflow/ReturnUrlTest.php

@@ -201,7 +201,7 @@ public function testExecuteAllowedOrderState($state)
 
         $this->eventManagerMock->expects($this->once())
             ->method('dispatch')
-            ->with('checkout_success', $this->arrayHasKey('order'));
+            ->with('paypal_checkout_success', $this->arrayHasKey('order'));
 
         $result = $this->returnUrl->execute();
         $this->assertNull($result);

app/code/Magento/Signifyd/etc/events.xml

@@ -12,7 +12,7 @@
     <event name="paypal_express_place_order_success">
         <observer name="signifyd_place_order_paypal_express_observer" instance="Magento\Signifyd\Observer\PlaceOrder"/>
     </event>
-    <event name="checkout_success">
+    <event name="paypal_checkout_success">
         <observer name="signifyd_place_order_checkout_success_observer" instance="Magento\Signifyd\Observer\PlaceOrder" />
     </event>
 </config>