heif: renaming of grid-{width,height} to tile-{width,height}

So that it's not confused with grid dimensions.

bug: 74831433

Change-Id: I29188c6527c2315cbc66157a0a5b68a0d11fecc4
diff --git a/media/extractors/mp4/ItemTable.cpp b/media/extractors/mp4/ItemTable.cpp
index c082fc1..666d68a 100644
--- a/media/extractors/mp4/ItemTable.cpp
+++ b/media/extractors/mp4/ItemTable.cpp
@@ -1471,8 +1471,8 @@
 
         // point image to the first tile for grid size and HVCC
         image = &mItemIdToItemMap.editValueAt(tileItemIndex);
-        meta->setInt32(kKeyGridWidth, image->width);
-        meta->setInt32(kKeyGridHeight, image->height);
+        meta->setInt32(kKeyTileWidth, image->width);
+        meta->setInt32(kKeyTileHeight, image->height);
         meta->setInt32(kKeyMaxInputSize, image->width * image->height * 1.5);
     }