Fix for bug 4371230.

- Generate unique ID for each DrmManagerClient in native side
- Fix the bug where multiple clients could use the same ID
- Return the correct unique ID back to Java
- Add a flag in the unique ID to separate native client and Java client

Change-Id: Ia4574b6b0a526f2335a65380975dc62f9a6e7f9b

drm/libdrmframework/DrmManagerClient.cpp

@@ -24,7 +24,7 @@ using namespace android;
 
 DrmManagerClient::DrmManagerClient():
         mUniqueId(0), mDrmManagerClientImpl(NULL) {
-    mDrmManagerClientImpl = DrmManagerClientImpl::create(&mUniqueId);
+    mDrmManagerClientImpl = DrmManagerClientImpl::create(&mUniqueId, true);
     mDrmManagerClientImpl->addClient(mUniqueId);
 }