MAGETWO-44261: fixed styles for mobile too

Author: dazvolt

app/design/frontend/Magento/blank/Magento_ProductVideo/web/css/source/_module.less

@@ -45,11 +45,14 @@
 }
 
 .product-video {
-    height: 88%;
-    margin-top: 5%;
+    height: 75%;
+    left: 0;
     position: absolute;
     top: 0;
     width: 100%;
+    right: 0;
+    bottom: 0;
+    margin: auto;
     iframe {
         height: 100%;
         left: 0;