media: rename VideoGrallocMetadata.hHandle to pHandle

This is so that it can be equivalent to the previously named
VideoDecoderOutputMetaData struct.

Bug: 13222807

Change-Id: I9463694f65436a7edb1f6b592efc0a6329232a27
diff --git a/include/media/hardware/HardwareAPI.h b/include/media/hardware/HardwareAPI.h
index a682ab7..5d2201b 100644
--- a/include/media/hardware/HardwareAPI.h
+++ b/include/media/hardware/HardwareAPI.h
@@ -100,14 +100,11 @@
 // dynamic buffer handling.
 struct VideoGrallocMetadata {
     MetadataBufferType eType;               // must be kMetadataBufferTypeGrallocSource
-    buffer_handle_t hHandle;
+    buffer_handle_t pHandle;
 };
 
 // Legacy name for VideoGrallocMetadata struct.
-struct VideoDecoderOutputMetaData {
-    MetadataBufferType eType;               // must be kMetadataBufferTypeGrallocSource
-    buffer_handle_t pHandle;
-};
+struct VideoDecoderOutputMetaData : public VideoGrallocMetadata {};
 
 struct VideoNativeMetadata {
     MetadataBufferType eType;               // must be kMetadataBufferTypeANWBuffer