Let getOriginalMimeType() take a fd passed from drm java applications

This patch enables the drm framework to avoid opening files directly.
As a result, the drm framework no longer needs the sdcard read permision.

o related-to-bug: 6426185

Change-Id: Ib176c35ef4b1a1a405e8e954f19a7985266f2510
diff --git a/drm/libdrmframework/include/DrmManagerClientImpl.h b/drm/libdrmframework/include/DrmManagerClientImpl.h
index f3d9315..9b4c9ae 100644
--- a/drm/libdrmframework/include/DrmManagerClientImpl.h
+++ b/drm/libdrmframework/include/DrmManagerClientImpl.h
@@ -148,10 +148,11 @@
      *
      * @param[in] uniqueId Unique identifier for a session
      * @param[in] path the path of the protected content
+     * @param[in] fd the file descriptor of the protected content
      * @return String8
      *     Returns mime-type of the original content, such as "video/mpeg"
      */
-    String8 getOriginalMimeType(int uniqueId, const String8& path);
+    String8 getOriginalMimeType(int uniqueId, const String8& path, int fd);
 
     /**
      * Retrieves the type of the protected object (content, rights, etc..)