Make software vp8 video encoder available to MediaCodec on Panda

Change-Id: I9ef1877c1a99cf5e463d16c070ab4872805e3384
diff --git a/media_codecs.xml b/media_codecs.xml
index 42ea4e9..4507a2d 100644
--- a/media_codecs.xml
+++ b/media_codecs.xml
@@ -96,5 +96,6 @@
         <MediaCodec name="OMX.google.amrwb.encoder" type="audio/amr-wb" />
         <MediaCodec name="OMX.google.aac.encoder" type="audio/mp4a-latm" />
         <MediaCodec name="OMX.google.flac.encoder" type="audio/flac" />
+        <MediaCodec name="OMX.google.vpx.encoder" type="video/x-vnd.on2.vp8" />
     </Encoders>
 </MediaCodecs>