Fix offline license requests and error events

Corrected a regression in error event reporting and a
mismatch in asset paths during rights acquisition.

Also requires https://android-git.corp.google.com/g/#/c/185898/

Contains Widevine libraries version 6.0.0-6957

Change-Id: I4a7603a86feaf437673fc73f0cccb6065dbcce67
related-to-bug: 6414503

proprietary/streamcontrol/include/WVStreamControlAPI.h

@@ -430,7 +430,7 @@ public:
 CLIENT_API WVStatus
 WV_Setup(WVSession *&session, WVFileSource *source, const std::string &transport,
         WVCredentials &credentials, WVOutputFormat outputFormat = WV_OutputFormat_PS,
-        unsigned long bufferSize = 10 * 1024 * 1024);
+         unsigned long bufferSize = 10 * 1024 * 1024, void *context = NULL);
 
 //
 // METHOD: WV_IsWidevineMedia