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/drmserver/DrmManagerService.cpp b/drm/drmserver/DrmManagerService.cpp
index 25a4e7b..bbd3b7f 100644
--- a/drm/drmserver/DrmManagerService.cpp
+++ b/drm/drmserver/DrmManagerService.cpp
@@ -125,9 +125,9 @@
     return mDrmManager->saveRights(uniqueId, drmRights, rightsPath, contentPath);
 }
 
-String8 DrmManagerService::getOriginalMimeType(int uniqueId, const String8& path) {
+String8 DrmManagerService::getOriginalMimeType(int uniqueId, const String8& path, int fd) {
     ALOGV("Entering getOriginalMimeType");
-    return mDrmManager->getOriginalMimeType(uniqueId, path);
+    return mDrmManager->getOriginalMimeType(uniqueId, path, fd);
 }
 
 int DrmManagerService::getDrmObjectType(