Upgrade xz-embedded to 3f438e15109229bb14ab45f285f4bff5412a9542 am: 6e6257f536

Original change: https://android-review.googlesource.com/c/platform/external/xz-embedded/+/1853701

Change-Id: I3cd0c179e6fe0c955fc945543c2255d6ca16ad61