Add padlocks to preferences that can be disabled by policy.

Change-Id: I43b6b5954ef6ec65b86d99321cabab9f49df842d
diff --git a/res/xml/sound_settings.xml b/res/xml/sound_settings.xml
index dd03fb0..2137490 100644
--- a/res/xml/sound_settings.xml
+++ b/res/xml/sound_settings.xml
@@ -59,7 +59,7 @@
                 android:summaryOff="@string/master_mono_off" />
 
         <!-- Interruptions -->
-        <PreferenceScreen
+        <com.android.settingslib.RestrictedPreference
                 android:key="zen_mode"
                 android:title="@string/zen_mode_settings_title"
                 settings:keywords="@string/keywords_sounds_and_notifications_interruptions"
@@ -89,14 +89,14 @@
                 android:persistent="false"
                 android:ringtoneType="alarm" />
 
-        <PreferenceScreen
+        <com.android.settingslib.RestrictedPreference
                 android:key="cell_broadcast_settings"
                 android:title="@string/cell_broadcast_settings" >
                 <intent
                         android:action="android.intent.action.MAIN"
                         android:targetPackage="com.android.cellbroadcastreceiver"
                         android:targetClass="com.android.cellbroadcastreceiver.CellBroadcastSettings" />
-        </PreferenceScreen>
+        </com.android.settingslib.RestrictedPreference>
 
         <!-- Other sounds -->
         <Preference