Upgrade rust/crates/xml-rs to 0.8.4 am: adee7a49d8 am: 34e83cf902 am: f6e86c2633 am: b041468558

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/xml-rs/+/1790991

Change-Id: I5cd4d401219a4abb7b59938d56c94ddeaabe30d9