Update parking_lot to 0.12.0 am: 468e33c5ab am: 6d325233ff am: b29cce9d8c am: bb8a50689a

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/parking_lot/+/2004796

Change-Id: I8f1c6330d2b0f2d32d57bc9973ffa1230efe6d8e