Add NightDisplaySettingsActivity

- The Settings#ACTION_NIGHT_DISPLAY_SETTINGS action can be used by apps
  to launch Night display settings directly.

Bug: 30291948
Change-Id: I5545bb7f0a467116454e5c44e207cbe91ddf9d43
diff --git a/src/com/android/settings/SettingsActivity.java b/src/com/android/settings/SettingsActivity.java
index 616cf8e..5b81c56 100644
--- a/src/com/android/settings/SettingsActivity.java
+++ b/src/com/android/settings/SettingsActivity.java
@@ -81,6 +81,7 @@
 import com.android.settings.deviceinfo.SimStatus;
 import com.android.settings.deviceinfo.Status;
 import com.android.settings.deviceinfo.StorageSettings;
+import com.android.settings.display.NightDisplaySettings;
 import com.android.settings.fuelgauge.BatterySaverSettings;
 import com.android.settings.fuelgauge.PowerUsageDetail;
 import com.android.settings.fuelgauge.PowerUsageSummary;
@@ -351,6 +352,7 @@
             WifiAPITest.class.getName(),
             WifiInfo.class.getName(),
             MasterClear.class.getName(),
+            NightDisplaySettings.class.getName(),
     };