Let Settings measure transient free space.

Transient volumes like USB drives are only mounted at /mnt/media_rw,
but they still appear in Settings > Storage.  To show stats like
free/used space, give Settings the permissions it needs to access
devices mounted there.

Bug: 22545248
Change-Id: I50be38f02f7d2bfe51d1ac0f76a04c340a21f936
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 1fef233..13e2218 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -9,6 +9,7 @@
 
     <original-package android:name="com.android.settings" />
 
+    <uses-permission android:name="android.permission.WRITE_MEDIA_STORAGE" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.WRITE_SETTINGS" />