MQE-849: Upgrading MTF PHP version to 7.2

 - fix tests

Author: okolesnyk

dev/tests/functional/tests/app/Magento/Catalog/Test/Constraint/AssertProductGridIsRendered.php

@@ -21,7 +21,7 @@ public function processAssert(
         \Magento\Catalog\Test\Page\Adminhtml\CatalogProductIndex $catalogProductIndex
     ) {
         $productId = $catalogProductIndex->open()->getProductGrid()->getFirstItemId();
-        \PHPUnit_Framework_Assert::assertNotNull(
+        \PHPUnit\Framework\Assert::assertNotNull(
             $productId,
             'Product grid is not rendered correctly.'
         );

dev/tests/functional/tests/app/Magento/Catalog/Test/Constraint/AssertResetFilterMessage.php

@@ -20,7 +20,7 @@ class AssertResetFilterMessage extends \Magento\Mtf\Constraint\AbstractConstrain
     public function processAssert(
         \Magento\Catalog\Test\Page\Adminhtml\CatalogProductIndex $catalogProductIndex
     ) {
-        \PHPUnit_Framework_Assert::assertContains(
+        \PHPUnit\Framework\Assert::assertContains(
             'restored the filter to its original state',
             $catalogProductIndex->getMessagesBlock()->getErrorMessage(),
             "Can't find proper message"