Sync released version of Instant Purchase (forward port from 2.2 to 2.3)

 - fixed Braintree PayPal integration with Instant Purchase

Author: Volodymyr Kublytskyi

app/code/Magento/Braintree/etc/config.xml

@@ -82,8 +82,7 @@
                 <title>Stored Accounts (Braintree PayPal)</title>
                 <can_use_internal>1</can_use_internal>
                 <instant_purchase>
-                    <available>Magento\Braintree\Model\InstantPurchase\CreditCard\AvailabilityChecker</available>
-                    <tokenFormat>Magento\Braintree\Model\InstantPurchase\CreditCard\TokenFormatter</tokenFormat>
+                    <tokenFormat>Magento\Braintree\Model\InstantPurchase\PayPal\TokenFormatter</tokenFormat>
                     <additionalInformation>Magento\Braintree\Model\InstantPurchase\PaymentAdditionalInformationProvider</additionalInformation>
                 </instant_purchase>
             </braintree_paypal_vault>