MAGETWO-98225: AuthorizenetAcceptjs broken for multi-shipping checkout

- Fixed option
- Added config test coverage

Author: nathanjosiah

app/code/Magento/AuthorizenetAcceptjs/etc/payment.xml

@@ -9,7 +9,7 @@
          xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Payment:etc/payment.xsd">
     <methods>
         <method name="authorizenet_acceptjs">
-            <allow_multiple_address>1</allow_multiple_address>
+            <allow_multiple_address>0</allow_multiple_address>
         </method>
     </methods>
 </payment>

dev/tests/integration/testsuite/Magento/AuthorizenetAcceptjs/Gateway/ConfigTest.php

@@ -8,6 +8,7 @@
 
 namespace Magento\AuthorizenetAcceptjs\Gateway;
 
+use Magento\Framework\Config\Data;
 use Magento\Payment\Model\Method\Adapter;
 use Magento\TestFramework\Helper\Bootstrap;
 use Magento\TestFramework\ObjectManager;
@@ -40,5 +41,11 @@ public function testVerifyConfiguration()
         $this->assertTrue($paymentAdapter->canUseInternal());
         $this->assertTrue($paymentAdapter->canEdit());
         $this->assertTrue($paymentAdapter->canFetchTransactionInfo());
+
+        /** @var Data $configReader */
+        $configReader = $this->objectManager->get('Magento\Payment\Model\Config\Data');
+        $value = $configReader->get('methods/authorizenet_acceptjs/allow_multiple_address');
+
+        $this->assertSame('0', $value);
     }
 }