Remove changing uids/timestamps from zip/jar files

Pass -X to zip so that Unix UID/GID and extra timestamps aren't
saved into the zip files.

Add a new tool, ziptime, that uses a very stripped down copy of
zipalign. It no longer depends on libandroidfw, and now rewrites the
timestamps in place instead of making a copy of the zipfile. This should
improve speed and reduce disk requirements, especially with the large
packaging zip files.

Bug: 24201956
Change-Id: I50f68669f659da1b4393e964ad40b6aafb00c1e7