Generate apex_available from c2a instead of a patch am: 2803aa42ec am: 46819d0a84 am: d3453b55c1

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/num-traits/+/1688681

Change-Id: I082e9c3d19256b06ac1dbb10e9a12af5c4587189