Fix futures-channel/METADATA am: 5dedceab5a am: 49babae9ee am: dc28ec101c am: 70f7120dc2

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/futures-channel/+/1414035

Change-Id: Ic736a080ef984f4f5cc5bfc4314b73cfc1dc2aa3