Generalize deapexer module to export any files

Previously, the deapexer module had to duplicate the java library
specific logic for constructing the path to the library's dex file in
the .apex file. That is not something that the deapexer needs to be
aware of, all it needs is a list of files that should be exported.

This change moves that logic into the prebuilt_apex/apex_set modules
and generalizes the deapexer module so that it can export any files
that are requested.

The deapexer module does still need to know which java modules need
access to exported files so it can add dependencies from them onto
itself. However, it does not need to know what the type of the module
is.

Bug: 186455808
Test: m nothing
      m SOONG_CONFIG_art_module_source_build=false nothing
Change-Id: I71c6f0f761efe3b6d66d54273786e98cd545811c