Generate apex_available from c2a instead of a patch am: d0234f2bbf am: 256379a292 am: 08d47934b0 am: ed39197f07

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/cfg-if/+/1688622

Change-Id: I1c6d8a488c8a940b01ef44938847fe6646cd41f9