Separate the key for audio sampling rate and video frame rate in MetaData.h

Change-Id: Ia33befaa7e6df8762703002d01aa79c04f15f040
diff --git a/media/libstagefright/CameraSource.cpp b/media/libstagefright/CameraSource.cpp
index 159d937..b8450fb 100644
--- a/media/libstagefright/CameraSource.cpp
+++ b/media/libstagefright/CameraSource.cpp
@@ -531,7 +531,7 @@
     mMeta->setInt32(kKeyHeight,      mVideoSize.height);
     mMeta->setInt32(kKeyStride,      mVideoSize.width);
     mMeta->setInt32(kKeySliceHeight, mVideoSize.height);
-    mMeta->setInt32(kKeySampleRate,  mVideoFrameRate);
+    mMeta->setInt32(kKeyFrameRate,   mVideoFrameRate);
     return OK;
 }