Remove the return Status from IGraphicBufferSource's functions.

Now, only the transport-level status is needed, so
::android::hardware::Status is sufficient.

Also simplify IOmxNode::sendCommand().

Test: Compiles

Bug: 31399200
Change-Id: Ia4cfc16681d19eb96f89d8db715fcc14516cb41a
diff --git a/media/omx/1.0/IOmxNode.hal b/media/omx/1.0/IOmxNode.hal
index 9483be4..5945b44 100644
--- a/media/omx/1.0/IOmxNode.hal
+++ b/media/omx/1.0/IOmxNode.hal
@@ -46,14 +46,14 @@
      * Invoke a command on the node.
      *
      * @param[in] cmd indicates the type of the command.
-     * @param[in] info holds information about the command.
+     * @param[in] param is a parameter for the command.
      * @param[out] status will be the status of the call.
      *
      * @see OMX_SendCommand() in the OpenMax IL standard.
      */
     sendCommand(
             uint32_t cmd,
-            Bytes info // TODO: describe structure better or point at standard
+            int32_t param
         ) generates (
             Status status
         );