Generate apex_available from c2a instead of a patch am: 4fa481b6ab am: c09fc84c6f am: e4add52767

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/futures-util/+/1688788

Change-Id: Idb861a2d2b33e6159c11e2200a2597d1974150d6