Recent changes to the rtsp code require every buffer fed to the packet source to have a timestamp, we're ignoring timestamps for gtalk videochat but we still have to have a placeholder.

Change-Id: Ib8615ce5a89a9a846ee2f9f96cdfb23462f72c7a
diff --git a/media/libstagefright/rtsp/ARTPSession.cpp b/media/libstagefright/rtsp/ARTPSession.cpp
index d2c56f7..f60c1a9 100644
--- a/media/libstagefright/rtsp/ARTPSession.cpp
+++ b/media/libstagefright/rtsp/ARTPSession.cpp
@@ -167,6 +167,7 @@
 #endif
 
             accessUnit->meta()->setInt64("ntp-time", ntpTime);
+            accessUnit->meta()->setInt64("timeUs", 0);
 
 #if 0
             int32_t damaged;