Offer to cache ringtones in system DE storage.

Ringtones often live on shared media, which is now encrypted with CE
keys and not available until after the user is unlocked.  To improve
the user experience while locked, cache the default ringtone,
notification sound, and alarm sound in a DE storage area.

Bug: 26730753
Change-Id: Ie6ad7790af4c87dd25759df3ed017e3b91a2fb87
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 770cde7..eda181b 100755
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -2780,6 +2780,11 @@
          */
         public static final Uri DEFAULT_RINGTONE_URI = getUriFor(RINGTONE);
 
+        /** {@hide} */
+        public static final String RINGTONE_CACHE = "ringtone_cache";
+        /** {@hide} */
+        public static final Uri RINGTONE_CACHE_URI = getUriFor(RINGTONE_CACHE);
+
         /**
          * Persistent store for the system-wide default notification sound.
          *
@@ -2798,6 +2803,11 @@
          */
         public static final Uri DEFAULT_NOTIFICATION_URI = getUriFor(NOTIFICATION_SOUND);
 
+        /** {@hide} */
+        public static final String NOTIFICATION_SOUND_CACHE = "notification_sound_cache";
+        /** {@hide} */
+        public static final Uri NOTIFICATION_SOUND_CACHE_URI = getUriFor(NOTIFICATION_SOUND_CACHE);
+
         /**
          * Persistent store for the system-wide default alarm alert.
          *
@@ -2816,6 +2826,11 @@
          */
         public static final Uri DEFAULT_ALARM_ALERT_URI = getUriFor(ALARM_ALERT);
 
+        /** {@hide} */
+        public static final String ALARM_ALERT_CACHE = "alarm_alert_cache";
+        /** {@hide} */
+        public static final Uri ALARM_ALERT_CACHE_URI = getUriFor(ALARM_ALERT_CACHE);
+
         /**
          * Persistent store for the system default media button event receiver.
          *