Use public APIs to update DND policies.

Bug: 22977552
Change-Id: I42d3da4052b9212505920b30bb2e24c3e56bc603
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 34898f5..3e69244 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -82,6 +82,7 @@
     <uses-permission android:name="android.permission.USER_ACTIVITY" />
     <uses-permission android:name="android.permission.CHANGE_APP_IDLE_STATE" />
     <uses-permission android:name="android.permission.PEERS_MAC_ADDRESS"/>
+    <uses-permission android:name="android.permission.MANAGE_NOTIFICATIONS"/>
 
     <application android:label="@string/settings_label"
             android:icon="@mipmap/ic_launcher_settings"