Don't package mke2fs and mke2fs.conf by default
These are not part of a standard yukawa build on aosp/master when following these instructions:
Add a --extra-host-files
argument instead.
With this argument, we can add back mke2fs and mke2fs.conf optionally, depending on the build target using:
--extra-host-files "mke2fs mke2fs.conf"