fastboot: `fastbootd` uses `libadbd.so`.

The size of `fastbootd` goes down from 64088-byte to 38488-byte
(aosp_taimen-userdebug) after the change.

Bug: 78793464
Test: `m -j installclean && m -j fastbootd`. Check that
      $OUT/recovery/root/system/lib64/libadbd.so exists and
      $OUT/recovery/root/system/bin/fastbootd depends on that.
Change-Id: Ic36c98da1a0dda4e0d86e671f858c42578f53f90