As per #30 (comment), I can confirm that interrupting the upload via interrupting the thread blocked on
client.uploadMediaItemCallable().futureCall(uploadRequest).get()
works.
However, as before, both
client.uploadMediaItem()
and
client.uploadMediaItemCallable().call(uploadRequest)
block uninterruptibly,
because ApiExceptions.callAndTranslateApiException calls Futures.getUnchecked(future), which blocks uninterruptibly by design.
I don't know in which situation one would ever want to block uninterruptibly to be honest. It's a road to unresponsive apps, leaking threads etc. Also, the behaviour should be symmetrical regardless of how you invoke the API. At the very least, the interrupt behaviour must be documented.