Add Night Light Suggestion and tests

Night Light settings suggestion will only show when the user
has not previously interacted with Night Light.

Bug: 37207263
Test: make ROBOTEST_FILTER=\
"(SettingsSuggestionsTest|SuggestionFeatureProviderImplTest)"\
RunSettingsRoboTests
Change-Id: I432d5fef19f5e4a52503da136b044598cb82164a
diff --git a/src/com/android/settings/Settings.java b/src/com/android/settings/Settings.java
index 38b6e1b..7892011 100644
--- a/src/com/android/settings/Settings.java
+++ b/src/com/android/settings/Settings.java
@@ -52,6 +52,7 @@
     public static class UserDictionarySettingsActivity extends SettingsActivity { /* empty */ }
     public static class DisplaySettingsActivity extends SettingsActivity { /* empty */ }
     public static class NightDisplaySettingsActivity extends SettingsActivity { /* empty */ }
+    public static class NightDisplaySuggestionActivity extends NightDisplaySettingsActivity { /* empty */ }
     public static class DeviceInfoSettingsActivity extends SettingsActivity { /* empty */ }
     public static class ApplicationSettingsActivity extends SettingsActivity { /* empty */ }
     public static class ManageApplicationsActivity extends SettingsActivity { /* empty */ }
@@ -65,7 +66,7 @@
                 return true;
             }
             return super.isValidFragment(className);
-            }
+        }
     }
     public static class BackgroundCheckSummaryActivity extends SettingsActivity { /* empty */ }
     public static class StorageUseActivity extends SettingsActivity { /* empty */ }