Upgrade xz-embedded to 1b6defd544914bfb4065e343296e5db64ef400e6

This project was upgraded with external_updater.
Usage: tools/external_updater/updater.sh update external/xz-embedded
For more info, check https://cs.android.com/android/platform/superproject/+/main:tools/external_updater/README.md

Test: TreeHugger
Change-Id: I0e4c4e28fa9f2e332d4dd3bcfffb0eff69329ff7