ANDROID: virtio_balloon: sysfs-configurable option bail_on_out_of_puff

New option available under (for some integer N):
/sys/bus/virtio/drivers/virtio_balloon/virtioN/bail_on_out_of_puff

Default value is 0 (disabled). When enabled, the balloon will stop
inflating on first allocation failure ("out of puff") until the next
virtio configuration change.

Bug: 407629285
Change-Id: Ic40b8edb651f396d1ecc7f391a92114209a67a31
Signed-off-by: Keir Fraser <keirf@google.com>