[Local NTP][Realbox] Adds left/right padding to realbox similar to fakebox

Bug: 1034997
Change-Id: If85a4399ecb99257e4733caba20dac70b5686488
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1985169
Auto-Submit: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Dan Beam <dbeam@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728277}

chrome/browser/resources/local_ntp/local_ntp.css

@@ -116,7 +116,8 @@ body.hide-fakebox #fakebox {
   visibility: hidden;
 }
 
-#fakebox-container {
+#fakebox-container,
+#realbox-container {
   margin: 0 auto 0 auto;
   /* Increase min-width again to account for the search icon: 390px new
    * min-width + additional 20px */