Oobe child specific sign in: update css and illustration file

Bug: 1101318
Change-Id: I7297f1522333927db4c14609c57747f79fe87829
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2366737Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Commit-Queue: Yunke Zhou <yunkez@google.com>
Cr-Commit-Position: refs/heads/master@{#800615}

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

@@ -8,11 +8,7 @@ found in the LICENSE file. -->
 
 <dom-module id="family-link-notice">
   <template>
-    <style include="oobe-dialog-host">
-      oobe-dialog {
-        --oobe-dialog-content-padding-top: 0;
-      }
-    </style>
+    <style include="oobe-dialog-host"></style>
     <oobe-dialog id="familyLinkDialog" role="dialog" has-buttons
         aria-label$="[[getDialogTitle_(locale, email_, domain_)]]">
       <hd-iron-icon slot="oobe-icon"

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

@@ -12,6 +12,7 @@ found in the LICENSE file. -->
       cr-card-radio-button {
         border-radius: 16px;
         height: 210px;
+        margin-bottom: 20px;
         --cr-button-edge-spacing: 0;
         --cr-card-radio-button-height: 100%;
         --cr-card-radio-button-padding: 0;
@@ -42,15 +43,15 @@ found in the LICENSE file. -->
         font-family: var(--oobe-header-font-family);
         font-size: 16px;
         font-weight: 500;
+        line-height: 24px;
+        padding-inline-end: 20px;
+        padding-inline-start: 20px;
         padding-top: 16px;
       }
 
       .card-text {
         color: var(--oobe-text-color);
-      }
-
-      oobe-dialog {
-        --oobe-dialog-content-padding-top: 0;
+        line-height: 20px;
       }
 
       .next-button {