Don't reference the notification led if it doesn't exist.

Bug: 27318491
Change-Id: Ic43f1e8c0c7cf376b19278ab6c2661abc1052ddb
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 2679da0..cf8eed9 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -6278,6 +6278,8 @@
 
     <!-- [CHAR LIMIT=130] Zen mode settings:  visual interruptions: screen is off: summary -->
     <string name="zen_mode_screen_off_summary">Prevent notifications silenced by Do Not Disturb from turning on the screen or pulsing the notification light</string>
+    <!-- [CHAR LIMIT=130] Zen mode settings:  visual interruptions: screen is off: summary -->
+    <string name="zen_mode_screen_off_summary_no_led">Prevent notifications silenced by Do Not Disturb from turning on the screen</string>
 
     <!-- [CHAR LIMIT=130] Zen mode settings:  visual interruptions summary -->
     <string name="zen_mode_all_visual_interruptions">Off</string>
diff --git a/src/com/android/settings/notification/ZenModeVisualInterruptionSettings.java b/src/com/android/settings/notification/ZenModeVisualInterruptionSettings.java
index a951a69..0a0acd1 100644
--- a/src/com/android/settings/notification/ZenModeVisualInterruptionSettings.java
+++ b/src/com/android/settings/notification/ZenModeVisualInterruptionSettings.java
@@ -55,6 +55,10 @@
         mPolicy = NotificationManager.from(mContext).getNotificationPolicy();
 
         mScreenOff = (SwitchPreference) root.findPreference(KEY_SCREEN_OFF);
+        if (!getResources()
+                .getBoolean(com.android.internal.R.bool.config_intrusiveNotificationLed)) {
+            mScreenOff.setSummary(R.string.zen_mode_screen_off_summary_no_led);
+        }
         mScreenOff.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
             @Override
             public boolean onPreferenceChange(Preference preference, Object newValue) {