Reverting this change to fix 2252466.

Specifying multiple ringtone types makes the volume stream change to ringer
instead of alarm. This prevents the user from changing the alarm volume inside
the picker.
diff --git a/res/xml/alarm_prefs.xml b/res/xml/alarm_prefs.xml
index b70a0b8..3ca8ed0 100644
--- a/res/xml/alarm_prefs.xml
+++ b/res/xml/alarm_prefs.xml
@@ -29,7 +29,7 @@
     <com.android.deskclock.AlarmPreference
         android:key="alarm"
         android:title="@string/alert"
-        android:ringtoneType="alarm|ringtone"
+        android:ringtoneType="alarm"
         android:persistent="false"
         android:showDefault="false"
         android:showSilent="true" />