Android mainline 12.0.0 release 85
Generate apex_available from c2a instead of a patch am: 798c708a18 am: 0a01c5a1c8 am: eaaa0489c9 am: b3d04ce05e

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/idna/+/1688778

Change-Id: I84f40f9d984b9b9b72569e1d1435a15ca07476b1