Merge "Make libfutures_channel available to DnsResolver" am: 196b0d2718 am: 53f76e6588 am: 0f3f50fac6 am: 335f1c1d4f

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/futures-channel/+/1741281

Change-Id: I169b160147ea93cdbbb2f63bd457bdaaeb32201f