modules: camera: Write back stream parameters

max_buffers and usage are read by the framework inside the struct used
to pass the stream configuration parameters;  scribble our new
calculated values whever they are updated internally.

Adds logging to stream creation method (reuse/new).

Change-Id: I04e12880820571900f2ae80c27100f8aedcf9d02
diff --git a/modules/camera/Stream.h b/modules/camera/Stream.h
index 521362e..34abd95 100644
--- a/modules/camera/Stream.h
+++ b/modules/camera/Stream.h
@@ -52,7 +52,7 @@
         // The camera device id this stream belongs to
         const int mId;
         // Handle to framework's stream, used as a cookie for buffers
-        const camera3_stream_t *mStream;
+        camera3_stream_t *mStream;
         // Stream type: CAMERA3_STREAM_* (see <hardware/camera3.h>)
         const int mType;
         // Width in pixels of the buffers in this stream