saf_util 2.0.0 leaves an already-answered MethodChannel.Result behind
in pendingResult: unrelated activity request codes consume (and answer)
the pending picker, and a failed picker launch replies without clearing
the pending state. The next delivery for request 1001 then replies a
second time — IllegalStateException "Reply already submitted" in
MainActivity.onActivityResult, crashing the process.
Vendored at packages/saf_util (BSD-3) with take-and-clear reply
ownership, request codes scoped to the plugin's own pickers, and a
guarded reply on the teardown race.