add IODIMetadata.cpp to makefile.am
add IODIMetadata.cpp to makefile.am

Summary:
redex-oss-build is failed with following:
```
Sandcastle failed executing step 'Build redex' for command 'lego' with exit code 1.
ERROR: missing files in Makefile.am
libredex/IODIMetadata.cpp
```

Reviewed By: emma0303

Differential Revision: D13657263

fbshipit-source-id: 4df92281c8cf4050ff524796ad58c12b75870863

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex