MAGETWO-60908: Image role can't be updated

Author: Bohdan Korablov

dev/tests/api-functional/testsuite/Magento/Catalog/Api/ProductAttributeMediaGalleryManagementInterfaceTest.php

@@ -237,8 +237,8 @@ public function testUpdate()
 
         $targetProduct = $this->getTargetSimpleProduct();
         $this->assertEquals('/m/a/magento_image.jpg', $targetProduct->getData('thumbnail'));
-        $this->assertNull($targetProduct->getData('image'));
-        $this->assertNull($targetProduct->getData('small_image'));
+        $this->assertEquals('no_selection', $targetProduct->getData('image'));
+        $this->assertEquals('no_selection', $targetProduct->getData('small_image'));
         $mediaGallery = $targetProduct->getData('media_gallery');
         $this->assertCount(1, $mediaGallery['images']);
         $updatedImage = array_shift($mediaGallery['images']);

dev/tests/integration/testsuite/Magento/Catalog/Model/Product/Gallery/ProcessorTest.php

@@ -146,15 +146,15 @@ public function testClearMediaAttribute()
         );
         $product->setData(['image' => 'test1', 'small_image' => 'test2', 'thumbnail' => 'test3']);
 
-        $this->assertNotEmpty($product->getData('image'));
+        $this->assertNotEquals('no_selection', $product->getData('image'));
         $this->_model->clearMediaAttribute($product, 'image');
-        $this->assertNull($product->getData('image'));
+        $this->assertEquals('no_selection', $product->getData('image'));
 
-        $this->assertNotEmpty($product->getData('small_image'));
-        $this->assertNotEmpty($product->getData('thumbnail'));
+        $this->assertNotEquals('no_selection', $product->getData('small_image'));
+        $this->assertNotEquals('no_selection', $product->getData('thumbnail'));
         $this->_model->clearMediaAttribute($product, ['small_image', 'thumbnail']);
-        $this->assertNull($product->getData('small_image'));
-        $this->assertNull($product->getData('thumbnail'));
+        $this->assertEquals('no_selection', $product->getData('small_image'));
+        $this->assertEquals('no_selection', $product->getData('thumbnail'));
     }
 
     public function testSetMediaAttribute()