Add lpunpack to otatools for rebuilding super.img

lpunpack is needed to repackage super.img for mixed-image virtual devices.
For Cuttlefish, it's included in host package. We need to include it in
otatools.zip so Goldfish or other devices can use it to mix their super images.
Necessary SOs are the same as lpmake and have been included in otatools.zip.

Bug: 134461288
Test: $ lunch aosp_x86-userdebug
      $ m otatools-package
      $ unzip -l $OUT/ota* | grep lpunpack
        467824  2008-01-01 00:00   bin/lpunpack

Change-Id: Ie2092f18afb88721b29b1738847a0b781dbcd431