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/DrmManager.h b/drm/libdrmframework/include/DrmManager.h
index 3942efe..491e8f7 100644
--- a/drm/libdrmframework/include/DrmManager.h
+++ b/drm/libdrmframework/include/DrmManager.h
@@ -85,7 +85,7 @@
     status_t saveRights(int uniqueId, const DrmRights& drmRights,
             const String8& rightsPath, const String8& contentPath);
 
-    String8 getOriginalMimeType(int uniqueId, const String8& path);
+    String8 getOriginalMimeType(int uniqueId, const String8& path, int fd);
 
     int getDrmObjectType(int uniqueId, const String8& path, const String8& mimeType);