DO NOT MERGE: Normalize paths for files in archives.

Always use leading slashes for paths, for simpler logic.

Bug: 31783726
Test: All tests pass.
Change-Id: I41f03880234086b6da0b85e726414c3550c7ce1f
(cherry picked from commit de9ec006ad198e7e793d1666edd1d5d9778c51de)
2 files changed