[automerger skipped] Make libfutures_io available to DnsResolver am: 8e3b624d16 -s ours

am skip reason: Merged-In I87ac190b5e1161b3281ab60348ad084ea3d859fe with SHA-1 cfe1f08cd8 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/rust/crates/futures-io/+/15067045

Change-Id: Ife2d8771ef80c12bc7b8979ccc0d13580efd4c56