Update TEST_MAPPING am: 6b2d941914

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/xml-rs/+/2106627

Change-Id: I54c1a7aad94d5c27ac1231e24f2745226fd63fcd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>