Initial import of crossbeam-channel-0.5.0. am: 2b588fff1a am: e1e2a30590 am: f86e43c1f2 am: 79befeec38

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/crossbeam-channel/+/1620977

Change-Id: I2b8c14e88bc157b8ed6f2e7fee348ccf86b572ad