What are available "Additional Metadata" keys in ARC welder

Question

I'm looking for the reference documentation for the "Additional Metadata" field in ARC Welder.

Here and there (also on SO) I can see answers mentioning specific keys (such as resize, formFactor, enableExternalDirectory, usePlayServices) but no reference to documentation. Is there any?

Answer 1

Looking through arc source code best I could find: https://chromium.googlesource.com/arc/arc/+/master/src/build/metadata/definitions.json which lists all the keys with some basic one-line help. I think this was previously used in the ARC Welder UI, but still hoping there is a bit more to the doc.