Revert "Revert "Build FUTILITY tool from futility-host.""

This reverts commit b9186f2b.

The cause of the earlier breakage has been identified and fixed by
commit 4b577413.

Bug: 35467608
Test: lunch ryu-userdebug; m otatools-package
Change-Id: I0ca329a3844b7d5d74443f7495b363e0f1c1c391