Add mode names to search results dynamically.

The resulting search result takes the user to the modes aggregator page.

Flag: android.app.modes_ui
Bug: 332937523
Test: ZenModesListPreferenceControllerTest, manual with modes_ui on and off
Change-Id: I7372307cb995667f6f7234530a3140f5295ab06a

src/com/android/settings/notification/modes/AbstractZenModePreferenceController.java

@@ -17,6 +17,7 @@
 package com.android.settings.notification.modes;
 
 import android.app.AutomaticZenRule;
+import android.app.Flags;
 import android.content.Context;
 
 import androidx.annotation.NonNull;
@@ -55,6 +56,11 @@ abstract class AbstractZenModePreferenceController extends AbstractPreferenceCon
         return mKey;
     }
 
+    @Override
+    public boolean isAvailable() {
+        return Flags.modesUi();
+    }
+
     // Called by the parent Fragment onStart, which means it will happen before resume.
     public void updateZenMode(@NonNull Preference preference, @NonNull ZenMode zenMode) {
         mZenMode = zenMode;