Upgrade rust/crates/async-task to 4.2.0 am: 549375c924 am: 5ba6603fdd am: 3e470bf5f7 am: db51179e4b am: d0c5041e08

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/async-task/+/2133020

Change-Id: I304d9e3af8f8735eccc3267208b800d4ed19321c
Signed-off-by: Automerger Merge Worker <[email protected]>