Prebuilt shared libraries should be collected for fuzz targets.

Currently, prebuilt shared libraries fail the linkable.CcLibrary()
check, as the module returned by NewPrebuiltSharedLibrary uses a
prebuiltLibraryLinker as the module.linker, rather than a
libraryDecorator (which is the check by CcLibrary()).

We also need to ensure that we discard LLNDK stubs libraries, so we
manually categorise and discard them as well. They unfortunately are are
cc.Modules that aren't CcLibraries, as they use a custom linker object
as well (stubDecorator).

Fixes: 144415986
Test: m fuzz
Change-Id: I3b85ef66d1602cb8c035a0a90bddf30674e2eb71