Hide Speedreader header when speedreader is hidden by admin policy (#31320)

browser/resources/settings/brave_content_page/content_page_index.html

@@ -32,12 +32,14 @@
     </settings-brave-content-playlist>
   </template>
 
-  <settings-brave-content-speedreader
-    id="speedreader"
-    slot="view"
-    prefs="{{prefs}}"
-    in-search-mode="[[inSearchMode_]]">
-  </settings-brave-content-speedreader>
+  <template is="dom-if" if="[[showPage_(pageVisibility_.speedreader)]]">
+    <settings-brave-content-speedreader
+      id="speedreader"
+      slot="view"
+      prefs="{{prefs}}"
+      in-search-mode="[[inSearchMode_]]">
+    </settings-brave-content-speedreader>
+  </template>
 
   <settings-appearance-fonts-page slot="view" id="fonts"
       data-parent-view-id="parent" prefs="{{prefs}}">

browser/resources/settings/brave_content_page/content_page_index.ts

@@ -67,7 +67,9 @@ SettingsBraveContentPageIndexElementBase implements SettingsPlugin {
     if (this.showPage_(this.pageVisibility_.playlist)) {
       views.push('playlist');
     }
-    views.push('speedreader');
+    if (this.showPage_(this.pageVisibility_.speedreader)) {
+      views.push('speedreader');
+    }
     this.$.viewManager.switchViews(views, 'no-animation', 'no-animation');
   }