Chrome OS: hide PIN setup card from Discover App.

Bug: 864686
Change-Id: I7032bd335ea625683176fc4d71c5285edecfc117
Reviewed-on: https://chromium-review.googlesource.com/c/1326224Reviewed-by: Wenzhao (Colin) Zang <wzang@chromium.org>
Commit-Queue: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606629}

chrome/browser/resources/chromeos/login/discover/discover_ui.html

@@ -40,9 +40,6 @@
       <discover-sync-files-card class="card" slot="cards"
           module="sync-files">
       </discover-sync-files-card>
-      <discover-pin-setup-card class="card" slot="cards"
-          module="pinSetup" on-click="onCardClick_">
-      </discover-pin-setup-card>
     </discover-welcome>
     <discover-pin-setup-module class="module"
         module="pinSetup" first-run="[[firstRun]]" hidden>

chrome/browser/resources/chromeos/login/discover/discover_welcome.css

@@ -5,7 +5,7 @@
 :host {
   --card-box-height: 208px;
   --card-box-width: 312px;
-  --card-rows: 3;
+  --card-rows: 2;
   --card-spacing: 16px;  /* Spacing between cards. */
   --dialog-height: 640px;
   --highlight-card-box-width: 640px;