Add placeholder on DND settings screen

Bug: 74321426
Test: make -j20 RunSettingsRoboTests
Change-Id: Icb7d21e342af85d1ad83e89efa2fe9a1d41e710b
diff --git a/res/xml/zen_mode_settings.xml b/res/xml/zen_mode_settings.xml
index 65fb7ab..a9bfdeb 100644
--- a/res/xml/zen_mode_settings.xml
+++ b/res/xml/zen_mode_settings.xml
@@ -42,6 +42,11 @@
         android:title="@string/zen_mode_automation_settings_title"
         android:fragment="com.android.settings.notification.ZenModeAutomationSettings" />
 
+    <!-- placeholder -->
+    <PreferenceCategory
+        android:key="dashboard_tile_placeholder"
+        android:order="5" />
+
     <!-- Turn on DND button -->
     <!-- Layout preference doesn't obey allowDividerAbove, so put it in a PreferenceCategory -->
     <PreferenceCategory
diff --git a/src/com/android/settings/dashboard/DashboardFragmentRegistry.java b/src/com/android/settings/dashboard/DashboardFragmentRegistry.java
index 29d66bd..22c7c8a 100644
--- a/src/com/android/settings/dashboard/DashboardFragmentRegistry.java
+++ b/src/com/android/settings/dashboard/DashboardFragmentRegistry.java
@@ -31,6 +31,7 @@
 import com.android.settings.network.NetworkDashboardFragment;
 import com.android.settings.notification.ConfigureNotificationSettings;
 import com.android.settings.notification.SoundSettings;
+import com.android.settings.notification.ZenModeSettings;
 import com.android.settings.security.LockscreenDashboardFragment;
 import com.android.settings.security.SecuritySettings;
 import com.android.settings.system.SystemDashboardFragment;
@@ -89,6 +90,8 @@
                 CategoryKey.CATEGORY_NOTIFICATIONS);
         PARENT_TO_CATEGORY_KEY_MAP.put(LockscreenDashboardFragment.class.getName(),
                 CategoryKey.CATEGORY_SECURITY_LOCKSCREEN);
+        PARENT_TO_CATEGORY_KEY_MAP.put(ZenModeSettings.class.getName(),
+                CategoryKey.CATEGORY_DO_NOT_DISTURB);
 
         CATEGORY_KEY_TO_PARENT_MAP = new ArrayMap<>(PARENT_TO_CATEGORY_KEY_MAP.size());