stagefright: untangle metadata-mode handling

- specify requested metadata mode from producers to OMX
- (pass requested metadata in IOMX::storeMetadataInBuffers)
- use correct logic for native handle source
- use native handle source for encoded meta buffers

Bug: 22775369
Change-Id: I58b03acd3e9a5367d5010d7f87b7af5cae23362c
diff --git a/media/libmediaplayerservice/Android.mk b/media/libmediaplayerservice/Android.mk
index 68860d2..8d86366 100644
--- a/media/libmediaplayerservice/Android.mk
+++ b/media/libmediaplayerservice/Android.mk
@@ -51,6 +51,7 @@
     $(TOP)/frameworks/av/include/media                              \
     $(TOP)/frameworks/av/include/camera                             \
     $(TOP)/frameworks/native/include/media/openmax                  \
+    $(TOP)/frameworks/native/include/media/hardware                 \
     $(TOP)/external/tremolo/Tremolo                                 \
     libcore/include                                                 \