AC-13828::Unable to place order with paypal express checkout when we are directly checking out from cart page

Author: glo60612

app/code/Magento/Quote/Model/CustomerManagement.php

@@ -159,7 +159,7 @@ public function validateAddresses(QuoteEntity $quote)
                 $quote->getShippingAddress()->getCustomerAddressId()
             );
         }
-        if (!empty($addresses) && $quote->getCustomerIsGuest()) {
+        if (empty($addresses) && $quote->getCustomerIsGuest() && $quote->getBillingAddress()->getTelephone()) {
             $billingAddress = $quote->getBillingAddress();
             $customerAddress = $this->customerAddressFactory->create();
             $customerAddress->setFirstname($billingAddress->getFirstname());

app/code/Magento/Quote/Test/Unit/Model/CustomerManagementTest.php

@@ -279,11 +279,11 @@ public function testValidateAddressesNotSavedInAddressBook()
             ->getMock();
         $this->addressFactoryMock->expects($this->exactly(1))->method('create')->willReturn($addressMock);
         $this->quoteMock
-            ->expects($this->any())
+            ->expects($this->atLeastOnce())
             ->method('getBillingAddress')
             ->willReturn($this->quoteAddressMock);
         $this->quoteMock
-            ->expects($this->any())
+            ->expects($this->atLeastOnce())
             ->method('getShippingAddress')
             ->willReturn($this->quoteAddressMock);
         $validatorMock = $this->getMockBuilder(Validator::class)