Update hiddenapi preupload checks to handle new location

The config/hiddenapi-*.txt files have moved so this change updates the
preupload scripts to match their new location.

Test: Modify the boot/hiddenapi/hiddenapi-*.txt files in various ways
      to verify the scripts fail.
Change-Id: I725458e809d9871b2c21bc4e18f62441aaa775a9