ACP2E-1120: add mftf

Author: alzota

app/code/Magento/Checkout/Test/Mftf/Test/AdminCheckZeroSubtotalOrderWithCustomStatus.xml

@@ -15,6 +15,7 @@
             <title value="Zero Subtotal Orders should have invoice generated when setting 'Automatically Invoice All Items' to Yes." />
             <description value="Created order should have invoice generated."/>
             <testCaseId value="ACP2E-1120"/>
+            <severity value="AVERAGE"/>
             <group value="checkout"/>
         </annotations>
         <before>

app/code/Magento/Checkout/Test/Mftf/Test/AdminCheckZeroSubtotalOrderWithGeneratedInvoiceTest.xml

@@ -14,7 +14,7 @@
             <stories value="ENGCOM-5443: Zero Subtotal Order with automatically invoice generated."/>
             <title value="Zero Subtotal Order should have invoice generated when setting 'Automatically Invoice All Items' to Yes." />
             <description value="Created order with automatically invoice generated."/>
-            <severity value="MAJOR"/>
+            <severity value="AVERAGE"/>
             <testCaseId value="ENGCOM-5443"/>
             <group value="checkout"/>
         </annotations>