ChromeOS: Learn More link on EULA screen should not trigger adjacent checkbox.

When user hits Enter on focused "Learn More" link of the EULA screen, adjacent
checkbox was involuntary triggered. This CL fixed it.

Bug: 771095
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I500ab0c41934c124a6ee1fa03a1ea7f62faf5485
Reviewed-on: https://chromium-review.googlesource.com/721892Reviewed-by: Wenzhao (Colin) Zang <wzang@chromium.org>
Commit-Queue: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509454}

chrome/browser/resources/chromeos/login/oobe_eula.html

@@ -72,13 +72,13 @@
         <div id="logging" class="layout horizontal">
           <paper-checkbox id="usageStats" checked="{{usageStatsChecked}}"
               on-change="onUsageChanged_">
-            <div id="usageStatsLabelContainer">
-              <span i18n-content="checkboxLogging"></span>
-              <a id="" href="#" i18n-content="learnMore"
-                  on-tap="onUsageStatsHelpLinkClicked_">
-              </a>
-            </div>
           </paper-checkbox>
+          <div id="usageStatsLabelContainer">
+            <span i18n-content="checkboxLogging"></span>
+            <a id="" href="#" i18n-content="learnMore"
+                on-tap="onUsageStatsHelpLinkClicked_">
+            </a>
+          </div>
         </div>
       </div>
       <div class="bottom-buttons flex layout horizontal">