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/DrmManager.cpp b/drm/drmserver/DrmManager.cpp
index 737edab..e7b0e90 100644
--- a/drm/drmserver/DrmManager.cpp
+++ b/drm/drmserver/DrmManager.cpp
@@ -266,12 +266,12 @@
     return result;
 }
 
-String8 DrmManager::getOriginalMimeType(int uniqueId, const String8& path) {
+String8 DrmManager::getOriginalMimeType(int uniqueId, const String8& path, int fd) {
     Mutex::Autolock _l(mLock);
     const String8 plugInId = getSupportedPlugInIdFromPath(uniqueId, path);
     if (EMPTY_STRING != plugInId) {
         IDrmEngine& rDrmEngine = mPlugInManager.getPlugIn(plugInId);
-        return rDrmEngine.getOriginalMimeType(uniqueId, path);
+        return rDrmEngine.getOriginalMimeType(uniqueId, path, fd);
     }
     return EMPTY_STRING;
 }