Auto grant read external storage too - it is now dangerous.

We grant external storage permissions to some default handlers by
default. Read external storage was promoted to runtime permission
but was not granted as a part of the external storage group, i.e.
with write external storage.

bug:21980225

Change-Id: I1edd7ae13222f12c9a488efb1919f5cf96e4b69d
diff --git a/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java b/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java
index fe3103b..62c686c 100644
--- a/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java
+++ b/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java
@@ -106,7 +106,7 @@
 
     private static final Set<String> STORAGE_PERMISSIONS = new ArraySet<>();
     static {
-//        STORAGE_PERMISSIONS.add(Manifest.permission.READ_EXTERNAL_STORAGE);
+        STORAGE_PERMISSIONS.add(Manifest.permission.READ_EXTERNAL_STORAGE);
         STORAGE_PERMISSIONS.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
     }