Upgrade toybox to f1efcb18a1acb898bb6ed52e1f6294df6718807d

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

Test: TreeHugger
Change-Id: Ie5319f39ca2ff0ed944fad2abcd280df65f032ae