Generate apex_available from c2a instead of a patch am: a907edecf9 am: cbe61bd42e am: 910869d321

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/serde/+/1689916

Change-Id: Iff973c7123dacddd9591d9e0243a504fbe75ed3b