[Nearby] Fix 'Learn More' link in device visibility 'zero state' page

Fixed: 1152626
Change-Id: Ia7afc348d46595522a6ab027c12e70771db1fb44
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2595512Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: James Vecore <vecore@google.com>
Commit-Queue: Shane Fitzpatrick <shanefitz@google.com>
Cr-Commit-Position: refs/heads/master@{#837919}

chrome/browser/resources/nearby_share/shared/nearby_contact_visibility.html

@@ -297,7 +297,9 @@
             <div id="zeroStateInfoContainer">
               <iron-icon id="zeroStateIcon" icon="cr:info"></iron-icon>
               <div class="cr-secondary-text">
-                $i18n{nearbyShareContactVisibilityZeroStateInfo}
+                <a href="$i18n{nearbyShareLearnMoreLink}" target="_blank">
+                  $i18n{nearbyShareContactVisibilityZeroStateInfo}
+                </a>
               </div>
             </div>
           </div>