Navi: Move check icon so it's 6px from edge to match mocks.

R=scottchen@chromium.org

Bug: 901210
Change-Id: I04a20fe0b81d2ca599865ae664915d0cac060317
Reviewed-on: https://chromium-review.googlesource.com/c/1340872Reviewed-by: Scott Chen <scottchen@chromium.org>
Commit-Queue: Hector Carmona <hcarmona@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609049}

chrome/browser/resources/welcome/onboarding_welcome/shared/chooser_shared_css.html

@@ -72,8 +72,8 @@
         height: 12px;
         margin: 0;
         position: absolute;
-        right: 10px;
-        top: 10px;
+        right: 6px;
+        top: 6px;
         width: 12px;
       }