It would be usefull to have back the convert images to WebP feature when exporting to android.
You are better off converting them yourself.
Check out my image encoding thread on the wiki & download XnConvert. Set it up exactly as it shows in the screenshots/tutorial bit I have provided.
Now you can batch convert your images to webp.
After you've done, create a backup copy of your current ved. Now open up your actual ved inside of a program like sublime text, atom or notepad++ & do a search for .png
& then click replace all & type .webp
. Then save the document & voila, you have replaced all png files with the webp versions you have created.
Might take you a few minutes or an hour or so depending on the amount of files you are batch converting.
P.S: I highly recommend sublime text - there's a free evaluation version, but if you want the next best thing, then I would have to recommend githubs Atom text editor which is almost as good as sublime & is 100% free.