Split datasource out of libstagefright

into libdatasource, which contains:
  DataSourceFactory
  (Clear)FileSource
  (Clear)MediaHTTP
  DataURISource
  HTTPBase
  NuCachedSource2

This is needed to break a circular dependency in an upcoming CL.

Test: build, boot

Change-Id: I34d9937235c78f18f51b18945342a0743e209577
diff --git a/media/libmediaplayerservice/MetadataRetrieverClient.cpp b/media/libmediaplayerservice/MetadataRetrieverClient.cpp
index b44eb43..fb228ca 100644
--- a/media/libmediaplayerservice/MetadataRetrieverClient.cpp
+++ b/media/libmediaplayerservice/MetadataRetrieverClient.cpp
@@ -37,6 +37,7 @@
 #include <media/MediaPlayerInterface.h>
 #include <media/stagefright/InterfaceUtils.h>
 #include <media/stagefright/Utils.h>
+#include <media/stagefright/FoundationUtils.h>
 #include <private/media/VideoFrame.h>
 #include "MetadataRetrieverClient.h"
 #include "StagefrightMetadataRetriever.h"