ACPT-1450: fix unit tests failures

Author: vzabaznov

app/code/Magento/SalesRule/Test/Unit/Model/ValidatorTest.php

@@ -560,7 +560,8 @@ public function testProcessShippingAmountActions(
 
         $ruleMock = $this->getMockBuilder(Rule::class)
             ->disableOriginalConstructor()
-            ->addMethods(['getApplyToShipping', 'getDiscountAmount', 'getSimpleAction'])
+            ->addMethods(['getApplyToShipping', 'getDiscountAmount'])
+            ->onlyMethods(['getSimpleAction'])
             ->getMock();
         $ruleMock->method('getApplyToShipping')
             ->willReturn(true);