Export list of "installable" files to soong_ui

These are a (partial) list of files that we'd install with a default
build. The idea is that if something is removed from this list, soong_ui
can remove it from the installed location before running ninja.

It's okay if there are things missing from this list, it's not intended
to be a 100% solution replacing installclean / CleanSpec.mk, just
something that handles 80% of the cases without user involvement.

In particular, if something is removed from PRODUCT_PACKAGES, we'll
remove it from disk, but not necessarily rebuild the image files. That's
the same as most use cases of CleanSpec.mk today, and often some other
change will trigger the necessary images to be rebuilt.

We should be able to fix that by changing all of the image creation
rules to depend on the (partial) list of files they care about, or by
fixing ninja to rebuild things when their list of dependencies change.
(Other tools run into this same problem)

The list of test files is also included so that we can remove obsolete
tests from their "installed" locations within test suites and the
testcases folders.

Test: remove a module from PRODUCT_PACKAGES, see the print and file removed
Test: change the name of a cts test, see the old one removed from cts
Change-Id: I67f270a6713369099ca523aaf991ee3beb815c0a