Upgrade rust/crates/futures-task to 0.3.5

* Update Android.bp with new feature and dependent package.
* New dependency of once_cell.

Test: mm in external/rust/crates
Change-Id: Ifb00f1733429665bcab486950d9813055b441a6f
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 0b4b62a..fdf27ca 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,19 +1,19 @@
 [package]
 name = "futures-task"
 edition = "2018"
-version = "0.3.4"
+version = "0.3.5"
 authors = ["Alex Crichton <alex@alexcrichton.com>"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/futures-rs"
 homepage = "https://rust-lang.github.io/futures-rs"
-documentation = "https://rust-lang.github.io/futures-api-docs/0.3.0-alpha.18/futures_core"
+documentation = "https://docs.rs/futures-task/0.3.5"
 description = """
 Tools for working with tasks.
 """
 
 [features]
 default = ["std"]
-std = ["alloc"]
+std = ["alloc", "once_cell"]
 alloc = []
 
 # Unstable features
@@ -23,6 +23,7 @@
 cfg-target-has-atomic = []
 
 [dependencies]
+once_cell = { version = "1.3.1", default-features = false, features = ["std"], optional = true }
 
 [package.metadata.docs.rs]
 all-features = true