Re-submit "Add genrules for merged removed.txt files"

No diffs vs monoliths. The TARGET_BUILD_APPS issue has been fixed.

Bug: 169034951
Test: for p in "" "system-" "module-lib-"; do
  for t in "current" "removed"; do
      echo "${p}${t}:"
      echo "$(diff -u0 \
          <($CANON frameworks/base/api/${p}${t}.txt | sort) \
          <($CANON out/soong/.intermediates/frameworks/base/api/frameworks-base-api-${p}${t}-merged.txt/gen/${p}${t}.txt | sort))"
  done
done
(cherry picked from commit cfb26e3b)

Change-Id: I1f637b69d96c0b86f4f30da6b68f06a382e50d28