dex_preopt: Use the unstripped jar file for generating profiles.

We were previously using LOCAL_BUILT_MODULE, which wouldn't work in the
case that "nostripping" wasn't specified (i.e when we stripped).

The issue is that the built module has its classes.dex entry stripped,
which means that profman can't do anything meaningful with it.

In this change, we use the right set of files for JAVA_LIBRARIES as well
as prebuilt PACKAGES. Fixing apps built from source is a larger task and
has been left for a future change. Depending on ART changes, we might
need to disable stripping for all apps and/or align userdebug and user
builds with each other. This will be tackled separately.

Test: make
Bug: 64896089
Change-Id: I4fd256d187b66763f354cc6001953469c2cd8fbb