[ContentExplorer] Download of preview not captured by responseInterceptor

I'm trying to use `responseInterceptor` prop in `ContentExplorer` to capture preview requests/responses.

However, I see that the request to load preview is not captured by `responseInterceptor` for some of the file types.

For text file, the request to load preview (*.boxcloud.com) is captured, but that's not the case for PDF and Excel files.

Here's the video that shows this and network logs collected while recording the video: https://app.box.com/s/p21mg3rvgkk6ic2u50nyhd1l894yq0yy

Here's the codepen I used for testing: https://codepen.io/kojimaru/pen/VwboWoe