Add DND Settings suggestion

Cherry-picked from pi-dev ag/4019736

Test: SettingsSuggestionsTest, ZenOnboardingActivityTest
Change-Id: Ie78c9cf8287ee56bc4596efe20d27f8eb432ab6c
Bug: 78445134

src/com/android/settings/notification/ZenSuggestionActivity.java

@@ -0,0 +1,24 @@
+package com.android.settings.notification;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Bundle;
+import android.provider.Settings;
+
+public class ZenSuggestionActivity extends Activity {
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        // start up zen settings activity
+        Intent settingsIntent = new Intent(Settings.ACTION_ZEN_MODE_SETTINGS);
+        startActivity(settingsIntent);
+
+        // start up onboarding activity
+        Intent onboardingActivity = new Intent(Settings.ZEN_MODE_ONBOARDING);
+        startActivity(onboardingActivity);
+
+        finish();
+    }
+}