MAGETWO-69089: [Backport] - Shipping address is sent as the billing address to Braintree - for 2.1

Author: Elena Marchenko

app/code/Magento/Braintree/view/frontend/web/template/payment/form.html

@@ -140,8 +140,11 @@
                         type="submit"
                         data-bind="
                         click: placeOrderClick,
-                        attr: {title: $t('Place Order')}
-                ">
+                        attr: {title: $t('Place Order')},
+                            css: {disabled: !isPlaceOrderActionAllowed()},
+                            enable: isActive()
+                        "
+                        disabled>
                     <span data-bind="i18n: 'Place Order'"></span>
                 </button>
             </div>