This is a request from the androidx team. There are bug fixes in 1.1 that should help customers.
tools/androidx/files.json looks like where it is defined
There are tests that depend on that verison number appearing in gradle check logs that will need to be updated (I think)
https://cs.opensource.google/search?q=androidx.window%20-language:java%20-filepath:lockfile&ss=flutter