Rename hiddenapi config files

Rename files to reflect new API list naming convention:
  light-greylist => greylist
  max-sdk-p-blacklist => greylist-max-p

This also removes unused files (private-dex.txt, public-dex.txt,
removed-dex.txt) and merges vendor.txt into greylist.txt.

Test: m appcompat
Test: frameworks/base/tools/hiddenapi/generate_hiddenapi_lists_test.py
Merged-In: I4922ecb011a03bef3fa105f8181d1851d2cc496a
Change-Id: I4922ecb011a03bef3fa105f8181d1851d2cc496a